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When I started I said that co2 stuff is too confusing I'll never do it. 6months later... I was going to start a nano tank and move to a larger marine tank come spring but my plans didn't happen before it got too cold to ship so my 10g is now a plant experiment tank. I just thought I'd start really simple took a 2liter bottle, cut a hole, shoved in some tubing, and stuck a bubble stone on the end. Eventually I'll make it more complicated but for now there are no fish in there and it took like 10mins to set it up. I put 2 cups sugar and 1 teaspoon yeast in warm water but.... I don't get much for bubbles. After 24hrs it bubbled some then started to die. If I wiggle the bottle a little I get bubbles otherwise there's not really anything. Is my mix wrong? Also my kh is 18-20 and my ph near 9 will that affect co2 or just make it hard for me to test the amount that's dissolved in the water?

Sham, the first thing you might want to check is if there are any leaks. Gas can easily escape through any tiny hole. A way to do this is get a soapy water solution, and smear it around where the tubing meets the 2-liter cap. if you see bubbles then there is a leak. You can use silicone to fix a leak, or try to make another 2-liter with a tighter fit.

A good mix for me (there are many yeast mixes out there) is 1.5 cups sugar, 1/4 to 1/2 teaspoon of yeast. I dissolve the sugar in a couple of cups of really hot water, then fill the 2 liter with cool water(this should end up being warm to the touch). The yeast you should activate seperately in warm water and add to the mix when the two temperatures are about the same. This is how I do it and my CO2 lasts about 2-3 weeks.

no matter the KH, your pH should drop the same amount. see here http://www.csd.net/~cgadd/aqua/art_plant_co2chart.htm

Last edited by mattyboombatty at 12-Nov-2004 14:50

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Critical Fertilator: The Micromanager of Macronutrients

Hi! I am looking to make my own Co2 setup. I had a question, you put a bubble stone on the end of what? I understand everything else but that....."stupid is as stupid does"...

thanks!

-pamela

sham is talking about putting an air stone on the end of the output tube. there are benefits of doing this as well as drawbacks. you don't really need it, and imho it only slows down the co2 as it comes out, creating backpressure into the 2L bottle.

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"That's the trouble with political jokes in this country... they get elected!" -- Dave Lippman

Already checked for leaks and added silicone. I put the stone on after it started bubbling and when I took it off today it stopped working completely. Maybe my yeast died for some unknown reason. Now I'm just getting little spurts of bubbles every so often. It's just not creating enough co2. I have to lift the tube up to only an inch underwater before I get a steady amount of bubbles. Even then it stops after a few mins.

that happens when the tube is placed into the tank too deep. the pressure of the water in the tank is greater than the pressure of co2 coming out. you can put the co2 tube directly into the top of a HOB filter and it will still give you a pretty good mix of co2 even though you will lose some to the agitation. (assuming you have a HOB filter )

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"That's the trouble with political jokes in this country... they get elected!" -- Dave Lippman

I used to have that same problem, and i discovered that if i took the bottle out of where it was (inside the cabinet, where is dark), it started producing bubbles like crazy i guess yeast also like light? I use the same mix you are using, 4 cups of tap water, 2 cups of sugar, and a teaspoon of yeast it usually works for about a month now.

No filter but I hooked it into the frame for a sponge filter and so the bubbles collect at the top edge and then bubble out when there's too many. It's working somewhat better. The only light it really gets is from the tank.. does yeast need light?

Wow I just measured 6.8ph. If I put that into the csd.net site it says I have 70-80ppm co2. I'm not 100% the kh on that tank but it's always measured 18-20 in my tanks. Well it works finally Now to wait and see how the plants do and then decide if I want to work with it in more detail and set up a system for my 55g. I tried to lower the ph of my water once and never got it below 8.4

70 - 80ppm is way too high for fish. If you think about putting some fish in you should make sure that there's no more than 25 - 30ppm CO2 in the water before you put the fish.

I agree that 70 to 80 ppm is too high for fish. Depending on how you measure your kH, it may be too high for the stability of your tank water. If your 30 is converted to German degrees of hardness, your kH is below 2. With a kH that low, you may create a pH crash that will kill any fish that you have remaining.

A good caution on a CO2 DIY without a pH controller is too never let them run overnight on a tank.

Last edited by Bob Wesolowski at 16-Nov-2004 02:56

__________
"To steal ideas from one person is plagiarism; to steal from many is research."
researched from Steven Wright

That's why I tried it on a tank with no fish first. I'm not gonna destroy my 55g by messing with alot of co2 before I know what I'm doing... Which I don't and somehow some of it must have gotten in the tank and now I have this white yeast smelling fuzzy stuff everywhere to clean up... Strip the tank and try again. Good thing about a smaller tank.

The yeast solution sometimes bubbles and rises, in the same way that a fizzy drink will do that if you shake it, and once some of the solution will get into the tubing, it will go into your tank. The best way to avoid this is by connecting the tube that comes out of the bottle with the solution to the top of an empty bottle. Another tube should come out of the top on the other side to the tank. Then, if any solution gets into the tubes, it will drip into the empty bottle rather than go into your tank.