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Re: [UniQuaria] co2

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  • Richard Bunn - Mannix & Co Solicitors
    I pulled the following of The Krib last year. Hope this helps. DIY CO2 Injection: The Yeast Method By Thomas Narten INTRODUCTION This article gives
    Message 1 of 51 , Mar 2, 2004
    • 0 Attachment
      I pulled the following of The Krib last year. Hope this helps.

      DIY CO2 Injection: The Yeast Method
      By Thomas
      Narten
      INTRODUCTION
      This article gives instructions for a cheap Do-It-Yourself
      CO2 injection system. The CO2 is produced by a mixture of
      sugar, yeast and water, and the setup is constructed entirely from cheap and
      readily available materials. Thanks go to Brian R Silverstein
      (silverst-at-armstrong.ecn.purdue.edu) for posting a description of his
      setup, which initially used sourdough starter. His message got me started
      and much of the information below comes from his postings. Not surprisingly,
      Brian thanks Ulli Kaeufl (hukaufl-at-eso.org) & George Booth
      (booth-at-hplvec.LVLD.HP.COM). Finally, a big thanks go to the many participants
      of the Usenet *.aquaria newsgroups, where this topic has been discussed many
      times, and numerous persons report positive results using this system.

      Warning: This setup may not be suitable for everyone. It requires regular
      fiddling and the uncertain CO2 injection rate may lead to pH
      fluctuations that can kill fish (especially if you have soft water). My water is
      fairly hard (GH 140-180 ppm) and the pH varies from 7.8 with no CO2
      to 7.0 with CO2. Read the FAQ on plants and CO2 injection
      before attempting this. CO2 is an important contributor to robust
      plant growth, but it is advisable to understand the big picture before going
      this route. It is particularly important to understand the relationship between
      pH, CO2 concentration and carbonate hardness. Note also that CO2 injection is a complete waste of time if one has inadequate
      light, as is typically the case with single-tube strip lights sold at most
      aquarium stores. One bulb usually produces an insufficient quantity of light,
      and typical bulbs do not produce the "full spectrum" of light plants require.

      On the other hand, the described set up is an inexpensive way to observe
      first hand the benefits of CO2 injection on plant growth. I
      personally had never seen what CO2 could do for a tank before trying
      it myself, and would probably never have purchased a conventional CO2
      injection system because of the high cost. In fact, I still haven't purchased
      one. I find the yeast method adequate for my current needs. I have been using it
      now for 8 months and have managed to acquire and successfully grow over 25
      species of plants with only a handful of failures. Here are the steps.

      CONSTRUCTING A CO2 GENERATOR
      The first step is to create a
      CO2 generator. I use a 2-liter plastic soft-drink container. The
      "hard" part is attaching a hose to the container so that the CO2
      doesn't leak out on its way to your aquarium. I use a number 3 rubber stopper
      with a 1/4 inch hole in the middle. A short segment of 1/4 inch copper tubing
      goes through the hole and connects to regular air hose tubing. I bought a stopper and copper tube from a campus chemical supply store for $ .45.

      Note: Other folks have had success attaching the tube directly to the
      resealable cap. Simply poke or drill a hole through the cap, stick the tubing
      through it and seal it with the aquarium silicone sealer. The variations are
      endless.

      BUILDING A CO2 REACTOR
      The second step is to create a
      CO2 reactor for trapping and dissolving the CO2 bubbles
      before they escape to the surface of your aquarium. Note: For the first few
      weeks, I simply placed an airstone at the bottom of the tank and let the
      CO2 bubble to the surface. While inefficient, enough CO2
      dissolved to make my plants grow noticably faster. Use of an airstone is
      suggested because the increased surface area of many small bubbles helps
      dissolve the CO2 faster.

      More recently, I constructed a "sophisticated" reactor. The idea is to trap
      the rising CO2 bubbles before they reach the surface and escape.
      Doing so provides two benefits. First, less escaping CO2 means more
      CO2 in your tank. Second, the trapped CO2 bubbles act as a
      (very!) crude gauge of how much CO2 you have in your tank. If a lot
      of CO2 is trapped, the amount of dissolved CO2 in your
      tank is likely to be high. If little CO2 is trapped, your rig may not
      be producing CO2 at a high enough rate to replace that used by plants
      or escaping from your tank.

      My reactor consists of a small clear plastic bowl that flower pots are placed
      on ($0.40 at any gardening store). I cut it in half, glued a clear piece of
      plastic to it and wedged it between the filter tube and aquarium glass just
      below one of the powerheads. The cutaway portion faces down creating a trap for
      rising CO2 bubbles. It is best to use clear plastic so that you can
      see how much CO2 is accumulating in the reactor.

      Other folks have had success with a more sophisticated reactor that actually
      circulates water in the reactor in order to dissolve the CO2 faster.
      A nice reactor can be made from the wide end of a gravel cleaner. The 1/2 inch
      tubing attached to such cleaners connects directly to the exit of many
      powerheads. The reactor catches the CO2 bubbles, while the water from
      the powerhead churns and dissolves the CO2 and then flows into the
      tank.

      Tetra also markets a "CO2 Bell", a simple reactor with suction
      cups that attach to the side of the tank. Since it is ready to go, it is the
      easiest to use, but finding them at local stores may be problematical, since few
      stores seem to market CO2 injection related products.

      If you use a cannister filter, another possibility is to let the
      CO2 bubble into the filter intake. The CO2 will completely
      dissolve by the time it exits the filter. The "gravel cleaner" reactor described
      above can be used to catch the CO2 with the hose connecting it to the
      filter intake.

      A SOURCE FOR CO2
      The third step is to create CO2.
      I mix 3/4 cup sugar, 6 cups water and a pinch of yeast (roughly 1 teaspoon does
      the trick). The exact ratio of ingredients is not critical. For example, I use
      enough water to fill the bottle to about 3 inches from the top. You don't want
      to get the mixture too full, as the mixture may foam a bit, and you don't want
      the foam flowing into your tank.

      Using the above mixture, I regularly get 10-14 days of strong CO2
      production, at a rate of one bubble every 3-7 seconds. When the system stops
      bubbling (the drop in gas production is often precipitous), dump out everything
      and mix up a new concoction.

      HINTS & DISCUSSION
      1) I doesn't hurt to shake the mixture every 2-3
      days. Early on it seemed to me that a mixture produced CO2 longer if
      I shook it every couple of days or so, but I am no longer sure that this is
      actually the case. (Note: it will be difficult to shake the mixture if it is too
      full!).

      2) Hot water contracts when cooled. Actually, the hot air trapped in your rig
      contracts when cooled. If your mixture is warmer than room temperature, it may
      suck water out of your tank before it starts producing enough CO2 to
      reverse the flow. If your CO2 rig sits below your aquarium,
      bad things could happen.

      One way to prevent problems is to insert a standard air valve between the
      mixture and the airstone. Right after mixing up a new batch, close the valve.
      Once the rig is producing CO2 again, open the valve.

      Rather than bother with a valve, I simply keep a spare 2-liter bottle on
      hand. When the current batch looks like it's starting to peter out (or before,
      if you don't want to have your tank's pH go up as CO2 production
      wanes), mix up a new batch, but don't connect it right away. Let it sit in a
      corner for 12-24 hours and then hook up the new mixture when you know it's going
      strong. That way there is no interruption in CO2 flow through your
      tank.

      Another possibility is to connect two separate mixtures together using gang
      valves (e.g., use a T-connector to attach both mixtures to the same airstone).
      Then, mix up a new batch in one rig while the other one is still going. The idea
      is to always have one of the mixtures going at full steam so that when one
      mixture quits, the other produces enough CO2 to keep your plants happy.

      3) Hot water kills yeast. If you dissolve yeast in hot water (like what comes
      out of my gas water heater), you probably won't get any CO2 from your
      setup. If you've mixed things up properly, you should get CO2
      production within a few hours, possibly more quickly; I've sometimes had things
      going 30 minutes after mixing a new batch. Here's what I do:

      Fill a 2 cup measuring cup with hot water, and dissolve the sugar in it.
      If you use a cup with a spout, you can pour the mixture directly into the soda
      bottle without a funnel (one less gadget to clean!)

      Add three more cups of cold water to the mixture and shake it up.

      Dissolve the yeast in a cup of cold water and add to mixture. I've only
      used bakers yeast, but others should work too.

      Add more cold water to mixture to fill to desired level. Shake the mixture
      well.

      Let sit at room temperature for a few hours until the mixture reaches room
      temperature. That's often all the time that is needed to get initial
      CO2 production going. I feel safer connecting my setup to the tank
      *after* I know that it is producing gas and won't suck water out of the tank.

      4) Some batches of yeast take longer get going than others. For
      example, yeast stored in a refrigerator takes longer to become active than yeast
      stored at room temperature. Letting the yeast sit out at room temperature
      overnight before adding it to your mixture reduces the startup delay. Another
      suggestion (from homebrewers) is to hydrate the yeast in a cup of warm (80 degree) water for 20 minutes before adding it to the sugar mixture.

      5) Nicholas Plummer reports that most people who advocate using a cannister
      filter as a reactor seem to have Eheims. When he tried bubbling gas into the
      intake of a fluval 203, the gas made the impeller rattle loudly when a bubble
      formed at the top of the cannister. He suspects that the slightly poorer design
      of the Fluval is to blame.

      Even without funneling CO2 into the filter, he gets the same
      effect (but to a lesser degree) late in the day. The water becomes so saturated
      with oxygen from photosynthesis that it starts to bubble out in the cannister.
      It reenters solution during the night and is always completely gone by the next
      morning. Perhaps the slight agitation of the water entering the cannister
      through an eheim surface extractor causes oxygen to precipitate out of solution.


      7) Some folks appear tempted to turn off the CO2 production at
      night and back on again in the morning. After all, plants consume oxygen at
      night and produce more CO2. This is a mistake. It is better to keep
      the tank's CO2 concentration relatively constant because a drop in
      the dissolved CO2 concentration leads to an increase in pH. Neither
      plants nor fish seem to appreciate rapid pH swings.

      8) Several persons report the appearance of an apparently harmless white film
      on their CO2 airstones. I have not witnessed this in my tank and am
      not sure of its cause.

      9) I am still experimenting with exact ratios of sugar, yeast and water. In
      my system, the rate of CO2 production is relatively steady for a
      number of days, but then drops precipitously (from several bubbles a minute to
      no production in 24-48 hours). I suspect that the yeast exhausts some trace
      element or other critical ingredient. Yeast needs a number of elements,
      including nitrogen (e.g., ammonia but not nitrate), magnesium, phosphorous,
      potassium, calcium, zinc, iron and copper. My initial hypothesis was that a
      buildup of alcohol limited yeast production. However, a homebrewing friend
      reports that it would take roughly 3.75 cups of sugar in a 2-liter bottle to
      produce enough alcohol to reach a concentration of 15%, the point at which no strain of yeast can survive. As another data point, I have been running a
      mixture now for over six weeks that is still producing an adequate amount of
      CO2. I have no explanation for the longevity of the current mixture.
      I used the same general recipe that previously worked for only two weeks.

      10) It should be possible to culture a new mixture using yeast from a
      previous batch. Simply save the sludge that collects at the bottom of a mixture.
      The top layer of sludge, which should be a bit lighter in color, consists of
      live but dormant yeast cells. The darker layer underneath is dead cells. I have
      not tried this myself. For more information, look towards the homebrewing field.


      RESULTS
      After some 15 years of mixed success at growing plants, I now
      have a jungle. I have to trim the growth in my 55g tank every 1-2 weeks. If I
      don't, plants completely cover the surface of the tank preventing light from
      reaching the lower levels. I have so many plants I'm throwing them away! My
      setup consists of:

      55g tank.

      2 40W bulbs (two 18-month old tritons).

      Temperature held at 78 degrees.

      UGF driven by 2 Aquaclear Powerhead 301s.

      Layer of floss between gravel and UGF plate.

      Some plants in gravel, some in "plant plugs", others in clay/plastic pots
      containing potting soil.

      Hard, alkaline water (tap pH 7.6+, GH 140-190 ppm).

      2 corys, 3 kribs, 5 otocinclus affinis, 2 pearl gouramis, 2 blue rams, 4
      medium angels and an angelicus cat.

      DIY yeast CO2 rig, airstone, and plastic CO2 bubble
      trap (not connected to powerhead)

      Regular addition of trace elements with iron.
      Without the
      CO2 rig, the measured CO2 concentration in my tank is
      about 1-2 ppm (according to the Lamotte CO2 test kit). With the
      CO2 rig, measured concentration ranges from 5-20 ppm, depending on
      what my bubble rate is. With CO2 injection, my pH drops from 7.8 to
      about 7.0 (at a CO2 concentration of 20 ppm). When the CO2
      runs out, pH rises again. Warning: The pH change can happen in less than 24
      hours, and some fish may suffer. To avoid this problem, hook up a new mixture before the old one has completely run out.

      I recently counted over 25 species of plants in my 55g tank. About 15 species
      I've had for eight months, the rest for about four. Most of the plants are doing
      extremely well. My major successes include hornwort, vallisneria, pennywort,
      elodea, foxtail, wisteria, ludwigia, java fern, rotala rotundifolia and both
      hygro. polysperma and carymbosa, which I throw out regularly.

      Other successes include willow moss, several swords, various cryptocorynes,
      alternanthera lilacinia, rotala macrandra, sagittaria, plus a few things I
      haven't been able to identify. My anubia nana doubled its size in four months,
      more growth than the entire previous year. It's growing a new leave every week.
      Last month, it bloomed for the first time.

      Some of the plants are not doing much, but they haven't died and rotted
      either. Part of the problem is that I don't have enough light reaching the
      bottom. The faster growing plants outcompete everything else. I have also
      witnessed a number of plants near the bottom struggling weeks to grow a few
      inches (even when under direct light), but after reaching a height of four or
      five inches, growth takes off. I'm convinced now that more light would help.

      My only true failure is cabomba. I had it growing very well for 2-3 months (I
      was throwing it away I had so much), but then growth just stopped. The plants
      got stringy looking and the leaves fell off. Since then I have learned that I
      probably don't have enough light for cabomba in my tank and my water is warmer
      (78 degrees) than ideal.

      It is now apparently also the case that my tank doesn't contain enough
      nitrogen to keep all plants growing at full steam. In the three months since
      purchasing a sensitive Lamotte nitrate test kit, nitrate levels have always
      registered zero. It is also apparent that some plants are growing at the expense
      of others. For example, elodea and foxtail growth was prolific at first, but now grows only slowly.

      SUMMARY
      In summary, the described sugar, yeast and water CO2
      injection system provides an inexpensive way to experiment with CO2 in a plant tank. It is particular attractive to those interested in trying
      CO2, but skeptical that benefits justify the cost of conventional
      systems. Although a bit more hassle to maintain than a proper tank-driven
      injection system, I do not find the burden to be excessive. Although I could
      afford to purchase the more expensive conventional system, I have little
      inclination to do so at this point. I spend much more time feeding my fish and
      trimming plants than I do fiddling with my rig.
      Thomas Narten
      16 Leto Rd.
      Albany, NY
      12203
      518-869-6958
      narten-at-cs.albany.edu
      Hypertext translation by E. Olson from Revision 3, 4/22/94

      Note: This document can be freely redistributed to other mailing lists,
      reprinted in local fish club bulletins, etc. as long as it is reprinted in its
      entirety and proper credit is given. If you want to reprint it, please contact
      me first in order to get the latest version. Further comments and suggestions
      are always appreciated.
      Revision 3 of this article appears in the May-June 1994 issue of "The Aquatic
      Gardener" (TAG). TAG is a publication produced by the Aquatic Gardening
      Association, which is dedicated to the dissemination of information concerning
      the growing of aquatic plants. Membership includes the bi-monthly TAG journal.
      For a one-year membership, send $15 (US dollars) to:

      Dorothy Reimer
      83 Cathcart St.
      London, Ontario
      Canada N6C
      3L9
      I strongly encourage plant enthusiasts to join this organization. I
      have found a lot of practical information on fertilizers, CO2 injection, etc in TAG. The best thing about TAG is that its contributers have
      lots of experience and success growing plants. Back issues are $3 each, and I
      think few people will disappointed at getting the last 1-2 years worth of back
      issues. Back issues are $3 each and can be ordered from
      Diana Walstad
      2303 Mt. Sinai Rd.
      Chapel Hill NC
      27514

      ----- Original Message -----
      From: HappyZot@...
      To: UniQuaria@yahoogroups.com
      Sent: Tuesday, March 02, 2004 10:39 AM
      Subject: [UniQuaria] co2


      Does anyone have the recipe for homemade co2 using soda bottles, tubing and yeast
      /Tiggy
    • Richard Bunn - Mannix & Co Solicitors
      I pulled the following of The Krib last year. Hope this helps. DIY CO2 Injection: The Yeast Method By Thomas Narten INTRODUCTION This article gives
      Message 51 of 51 , Mar 2, 2004
      • 0 Attachment
        I pulled the following of The Krib last year. Hope this helps.

        DIY CO2 Injection: The Yeast Method
        By Thomas
        Narten
        INTRODUCTION
        This article gives instructions for a cheap Do-It-Yourself
        CO2 injection system. The CO2 is produced by a mixture of
        sugar, yeast and water, and the setup is constructed entirely from cheap and
        readily available materials. Thanks go to Brian R Silverstein
        (silverst-at-armstrong.ecn.purdue.edu) for posting a description of his
        setup, which initially used sourdough starter. His message got me started
        and much of the information below comes from his postings. Not surprisingly,
        Brian thanks Ulli Kaeufl (hukaufl-at-eso.org) & George Booth
        (booth-at-hplvec.LVLD.HP.COM). Finally, a big thanks go to the many participants
        of the Usenet *.aquaria newsgroups, where this topic has been discussed many
        times, and numerous persons report positive results using this system.

        Warning: This setup may not be suitable for everyone. It requires regular
        fiddling and the uncertain CO2 injection rate may lead to pH
        fluctuations that can kill fish (especially if you have soft water). My water is
        fairly hard (GH 140-180 ppm) and the pH varies from 7.8 with no CO2
        to 7.0 with CO2. Read the FAQ on plants and CO2 injection
        before attempting this. CO2 is an important contributor to robust
        plant growth, but it is advisable to understand the big picture before going
        this route. It is particularly important to understand the relationship between
        pH, CO2 concentration and carbonate hardness. Note also that CO2 injection is a complete waste of time if one has inadequate
        light, as is typically the case with single-tube strip lights sold at most
        aquarium stores. One bulb usually produces an insufficient quantity of light,
        and typical bulbs do not produce the "full spectrum" of light plants require.

        On the other hand, the described set up is an inexpensive way to observe
        first hand the benefits of CO2 injection on plant growth. I
        personally had never seen what CO2 could do for a tank before trying
        it myself, and would probably never have purchased a conventional CO2
        injection system because of the high cost. In fact, I still haven't purchased
        one. I find the yeast method adequate for my current needs. I have been using it
        now for 8 months and have managed to acquire and successfully grow over 25
        species of plants with only a handful of failures. Here are the steps.

        CONSTRUCTING A CO2 GENERATOR
        The first step is to create a
        CO2 generator. I use a 2-liter plastic soft-drink container. The
        "hard" part is attaching a hose to the container so that the CO2
        doesn't leak out on its way to your aquarium. I use a number 3 rubber stopper
        with a 1/4 inch hole in the middle. A short segment of 1/4 inch copper tubing
        goes through the hole and connects to regular air hose tubing. I bought a stopper and copper tube from a campus chemical supply store for $ .45.

        Note: Other folks have had success attaching the tube directly to the
        resealable cap. Simply poke or drill a hole through the cap, stick the tubing
        through it and seal it with the aquarium silicone sealer. The variations are
        endless.

        BUILDING A CO2 REACTOR
        The second step is to create a
        CO2 reactor for trapping and dissolving the CO2 bubbles
        before they escape to the surface of your aquarium. Note: For the first few
        weeks, I simply placed an airstone at the bottom of the tank and let the
        CO2 bubble to the surface. While inefficient, enough CO2
        dissolved to make my plants grow noticably faster. Use of an airstone is
        suggested because the increased surface area of many small bubbles helps
        dissolve the CO2 faster.

        More recently, I constructed a "sophisticated" reactor. The idea is to trap
        the rising CO2 bubbles before they reach the surface and escape.
        Doing so provides two benefits. First, less escaping CO2 means more
        CO2 in your tank. Second, the trapped CO2 bubbles act as a
        (very!) crude gauge of how much CO2 you have in your tank. If a lot
        of CO2 is trapped, the amount of dissolved CO2 in your
        tank is likely to be high. If little CO2 is trapped, your rig may not
        be producing CO2 at a high enough rate to replace that used by plants
        or escaping from your tank.

        My reactor consists of a small clear plastic bowl that flower pots are placed
        on ($0.40 at any gardening store). I cut it in half, glued a clear piece of
        plastic to it and wedged it between the filter tube and aquarium glass just
        below one of the powerheads. The cutaway portion faces down creating a trap for
        rising CO2 bubbles. It is best to use clear plastic so that you can
        see how much CO2 is accumulating in the reactor.

        Other folks have had success with a more sophisticated reactor that actually
        circulates water in the reactor in order to dissolve the CO2 faster.
        A nice reactor can be made from the wide end of a gravel cleaner. The 1/2 inch
        tubing attached to such cleaners connects directly to the exit of many
        powerheads. The reactor catches the CO2 bubbles, while the water from
        the powerhead churns and dissolves the CO2 and then flows into the
        tank.

        Tetra also markets a "CO2 Bell", a simple reactor with suction
        cups that attach to the side of the tank. Since it is ready to go, it is the
        easiest to use, but finding them at local stores may be problematical, since few
        stores seem to market CO2 injection related products.

        If you use a cannister filter, another possibility is to let the
        CO2 bubble into the filter intake. The CO2 will completely
        dissolve by the time it exits the filter. The "gravel cleaner" reactor described
        above can be used to catch the CO2 with the hose connecting it to the
        filter intake.

        A SOURCE FOR CO2
        The third step is to create CO2.
        I mix 3/4 cup sugar, 6 cups water and a pinch of yeast (roughly 1 teaspoon does
        the trick). The exact ratio of ingredients is not critical. For example, I use
        enough water to fill the bottle to about 3 inches from the top. You don't want
        to get the mixture too full, as the mixture may foam a bit, and you don't want
        the foam flowing into your tank.

        Using the above mixture, I regularly get 10-14 days of strong CO2
        production, at a rate of one bubble every 3-7 seconds. When the system stops
        bubbling (the drop in gas production is often precipitous), dump out everything
        and mix up a new concoction.

        HINTS & DISCUSSION
        1) I doesn't hurt to shake the mixture every 2-3
        days. Early on it seemed to me that a mixture produced CO2 longer if
        I shook it every couple of days or so, but I am no longer sure that this is
        actually the case. (Note: it will be difficult to shake the mixture if it is too
        full!).

        2) Hot water contracts when cooled. Actually, the hot air trapped in your rig
        contracts when cooled. If your mixture is warmer than room temperature, it may
        suck water out of your tank before it starts producing enough CO2 to
        reverse the flow. If your CO2 rig sits below your aquarium,
        bad things could happen.

        One way to prevent problems is to insert a standard air valve between the
        mixture and the airstone. Right after mixing up a new batch, close the valve.
        Once the rig is producing CO2 again, open the valve.

        Rather than bother with a valve, I simply keep a spare 2-liter bottle on
        hand. When the current batch looks like it's starting to peter out (or before,
        if you don't want to have your tank's pH go up as CO2 production
        wanes), mix up a new batch, but don't connect it right away. Let it sit in a
        corner for 12-24 hours and then hook up the new mixture when you know it's going
        strong. That way there is no interruption in CO2 flow through your
        tank.

        Another possibility is to connect two separate mixtures together using gang
        valves (e.g., use a T-connector to attach both mixtures to the same airstone).
        Then, mix up a new batch in one rig while the other one is still going. The idea
        is to always have one of the mixtures going at full steam so that when one
        mixture quits, the other produces enough CO2 to keep your plants happy.

        3) Hot water kills yeast. If you dissolve yeast in hot water (like what comes
        out of my gas water heater), you probably won't get any CO2 from your
        setup. If you've mixed things up properly, you should get CO2
        production within a few hours, possibly more quickly; I've sometimes had things
        going 30 minutes after mixing a new batch. Here's what I do:

        Fill a 2 cup measuring cup with hot water, and dissolve the sugar in it.
        If you use a cup with a spout, you can pour the mixture directly into the soda
        bottle without a funnel (one less gadget to clean!)

        Add three more cups of cold water to the mixture and shake it up.

        Dissolve the yeast in a cup of cold water and add to mixture. I've only
        used bakers yeast, but others should work too.

        Add more cold water to mixture to fill to desired level. Shake the mixture
        well.

        Let sit at room temperature for a few hours until the mixture reaches room
        temperature. That's often all the time that is needed to get initial
        CO2 production going. I feel safer connecting my setup to the tank
        *after* I know that it is producing gas and won't suck water out of the tank.

        4) Some batches of yeast take longer get going than others. For
        example, yeast stored in a refrigerator takes longer to become active than yeast
        stored at room temperature. Letting the yeast sit out at room temperature
        overnight before adding it to your mixture reduces the startup delay. Another
        suggestion (from homebrewers) is to hydrate the yeast in a cup of warm (80 degree) water for 20 minutes before adding it to the sugar mixture.

        5) Nicholas Plummer reports that most people who advocate using a cannister
        filter as a reactor seem to have Eheims. When he tried bubbling gas into the
        intake of a fluval 203, the gas made the impeller rattle loudly when a bubble
        formed at the top of the cannister. He suspects that the slightly poorer design
        of the Fluval is to blame.

        Even without funneling CO2 into the filter, he gets the same
        effect (but to a lesser degree) late in the day. The water becomes so saturated
        with oxygen from photosynthesis that it starts to bubble out in the cannister.
        It reenters solution during the night and is always completely gone by the next
        morning. Perhaps the slight agitation of the water entering the cannister
        through an eheim surface extractor causes oxygen to precipitate out of solution.


        7) Some folks appear tempted to turn off the CO2 production at
        night and back on again in the morning. After all, plants consume oxygen at
        night and produce more CO2. This is a mistake. It is better to keep
        the tank's CO2 concentration relatively constant because a drop in
        the dissolved CO2 concentration leads to an increase in pH. Neither
        plants nor fish seem to appreciate rapid pH swings.

        8) Several persons report the appearance of an apparently harmless white film
        on their CO2 airstones. I have not witnessed this in my tank and am
        not sure of its cause.

        9) I am still experimenting with exact ratios of sugar, yeast and water. In
        my system, the rate of CO2 production is relatively steady for a
        number of days, but then drops precipitously (from several bubbles a minute to
        no production in 24-48 hours). I suspect that the yeast exhausts some trace
        element or other critical ingredient. Yeast needs a number of elements,
        including nitrogen (e.g., ammonia but not nitrate), magnesium, phosphorous,
        potassium, calcium, zinc, iron and copper. My initial hypothesis was that a
        buildup of alcohol limited yeast production. However, a homebrewing friend
        reports that it would take roughly 3.75 cups of sugar in a 2-liter bottle to
        produce enough alcohol to reach a concentration of 15%, the point at which no strain of yeast can survive. As another data point, I have been running a
        mixture now for over six weeks that is still producing an adequate amount of
        CO2. I have no explanation for the longevity of the current mixture.
        I used the same general recipe that previously worked for only two weeks.

        10) It should be possible to culture a new mixture using yeast from a
        previous batch. Simply save the sludge that collects at the bottom of a mixture.
        The top layer of sludge, which should be a bit lighter in color, consists of
        live but dormant yeast cells. The darker layer underneath is dead cells. I have
        not tried this myself. For more information, look towards the homebrewing field.


        RESULTS
        After some 15 years of mixed success at growing plants, I now
        have a jungle. I have to trim the growth in my 55g tank every 1-2 weeks. If I
        don't, plants completely cover the surface of the tank preventing light from
        reaching the lower levels. I have so many plants I'm throwing them away! My
        setup consists of:

        55g tank.

        2 40W bulbs (two 18-month old tritons).

        Temperature held at 78 degrees.

        UGF driven by 2 Aquaclear Powerhead 301s.

        Layer of floss between gravel and UGF plate.

        Some plants in gravel, some in "plant plugs", others in clay/plastic pots
        containing potting soil.

        Hard, alkaline water (tap pH 7.6+, GH 140-190 ppm).

        2 corys, 3 kribs, 5 otocinclus affinis, 2 pearl gouramis, 2 blue rams, 4
        medium angels and an angelicus cat.

        DIY yeast CO2 rig, airstone, and plastic CO2 bubble
        trap (not connected to powerhead)

        Regular addition of trace elements with iron.
        Without the
        CO2 rig, the measured CO2 concentration in my tank is
        about 1-2 ppm (according to the Lamotte CO2 test kit). With the
        CO2 rig, measured concentration ranges from 5-20 ppm, depending on
        what my bubble rate is. With CO2 injection, my pH drops from 7.8 to
        about 7.0 (at a CO2 concentration of 20 ppm). When the CO2
        runs out, pH rises again. Warning: The pH change can happen in less than 24
        hours, and some fish may suffer. To avoid this problem, hook up a new mixture before the old one has completely run out.

        I recently counted over 25 species of plants in my 55g tank. About 15 species
        I've had for eight months, the rest for about four. Most of the plants are doing
        extremely well. My major successes include hornwort, vallisneria, pennywort,
        elodea, foxtail, wisteria, ludwigia, java fern, rotala rotundifolia and both
        hygro. polysperma and carymbosa, which I throw out regularly.

        Other successes include willow moss, several swords, various cryptocorynes,
        alternanthera lilacinia, rotala macrandra, sagittaria, plus a few things I
        haven't been able to identify. My anubia nana doubled its size in four months,
        more growth than the entire previous year. It's growing a new leave every week.
        Last month, it bloomed for the first time.

        Some of the plants are not doing much, but they haven't died and rotted
        either. Part of the problem is that I don't have enough light reaching the
        bottom. The faster growing plants outcompete everything else. I have also
        witnessed a number of plants near the bottom struggling weeks to grow a few
        inches (even when under direct light), but after reaching a height of four or
        five inches, growth takes off. I'm convinced now that more light would help.

        My only true failure is cabomba. I had it growing very well for 2-3 months (I
        was throwing it away I had so much), but then growth just stopped. The plants
        got stringy looking and the leaves fell off. Since then I have learned that I
        probably don't have enough light for cabomba in my tank and my water is warmer
        (78 degrees) than ideal.

        It is now apparently also the case that my tank doesn't contain enough
        nitrogen to keep all plants growing at full steam. In the three months since
        purchasing a sensitive Lamotte nitrate test kit, nitrate levels have always
        registered zero. It is also apparent that some plants are growing at the expense
        of others. For example, elodea and foxtail growth was prolific at first, but now grows only slowly.

        SUMMARY
        In summary, the described sugar, yeast and water CO2
        injection system provides an inexpensive way to experiment with CO2 in a plant tank. It is particular attractive to those interested in trying
        CO2, but skeptical that benefits justify the cost of conventional
        systems. Although a bit more hassle to maintain than a proper tank-driven
        injection system, I do not find the burden to be excessive. Although I could
        afford to purchase the more expensive conventional system, I have little
        inclination to do so at this point. I spend much more time feeding my fish and
        trimming plants than I do fiddling with my rig.
        Thomas Narten
        16 Leto Rd.
        Albany, NY
        12203
        518-869-6958
        narten-at-cs.albany.edu
        Hypertext translation by E. Olson from Revision 3, 4/22/94

        Note: This document can be freely redistributed to other mailing lists,
        reprinted in local fish club bulletins, etc. as long as it is reprinted in its
        entirety and proper credit is given. If you want to reprint it, please contact
        me first in order to get the latest version. Further comments and suggestions
        are always appreciated.
        Revision 3 of this article appears in the May-June 1994 issue of "The Aquatic
        Gardener" (TAG). TAG is a publication produced by the Aquatic Gardening
        Association, which is dedicated to the dissemination of information concerning
        the growing of aquatic plants. Membership includes the bi-monthly TAG journal.
        For a one-year membership, send $15 (US dollars) to:

        Dorothy Reimer
        83 Cathcart St.
        London, Ontario
        Canada N6C
        3L9
        I strongly encourage plant enthusiasts to join this organization. I
        have found a lot of practical information on fertilizers, CO2 injection, etc in TAG. The best thing about TAG is that its contributers have
        lots of experience and success growing plants. Back issues are $3 each, and I
        think few people will disappointed at getting the last 1-2 years worth of back
        issues. Back issues are $3 each and can be ordered from
        Diana Walstad
        2303 Mt. Sinai Rd.
        Chapel Hill NC
        27514

        ----- Original Message -----
        From: HappyZot@...
        To: UniQuaria@yahoogroups.com
        Sent: Tuesday, March 02, 2004 10:39 AM
        Subject: [UniQuaria] co2


        Does anyone have the recipe for homemade co2 using soda bottles, tubing and yeast
        /Tiggy
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