DYI CO2 Failure

[Zorfox]

So I recently setup a 55 Gallon planted tank, link to the original setup post here. I have seen sunken neons (you know the ones you miss until they look like a cotton ball lol), ferocious green hair algae covering the tank in days (partially fixed) and now my last ditch attempt to use a DYI CO2 device correctly. It seems the delivery is not consistent enough to deliver a constant flow. I may see 15 bubbles a second or one every few seconds. Some mixes are slow and die quickly. Others, fast furious and burn out. What is the trick? Obviously people are doing it successfully. I have do be doing something wrong here.

Below are two images of my setup. See if you can spot the problem. I usually use R/O water from a vending machine. I proof the yeast until it is quite active. Add to the large container and water with 2 cups of table sugar. Cap it and wait.


I have an exhaust and tank reservoir controlled by valves. I balance the flow with those two valves.

[Hoppy]

This definitely does work: http://www.plantedtank.net/forums/sh...d.php?t=178503

Are those little valves, the white things in the CO2 line? Why?

[aznartist34]

People normally use tap water because the process makes the liquid acidic and the low ph will kill of the yeast.

[Hoppy]

The water/yeast/sugar should almost fill the bottle, like up just beyond where it starts to neck down. You need to minimize the amount of air in the bottle at the start, or it takes a long time for the bubbles you see coming out to be mostly CO2 instead of mostly air. And, if you use some baking soda in the mix I find it lasts longer, and gives a more stable bubble rate. I use equal measures of yeast and baking soda.

[Zorfox]

Thanks for the replies. I never thought about not having the air at the top of the container. Good advice. I will certainly try the baking soda mix. I have no idea if it will help my tap is VERY hard.

Those white things are valves. Without valves I have no control over the bubble rate. If I have excess, I open the exhaust valve to prevent the container from cracking under pressure. Each of the small bottles serve as bubble counters as well.

[Diana]

RO has no minerals for the yeast to grow. I add a TINY pinch of KH2PO4 to the mix, and use tap water (GH and KH about 4 degrees).

I use soda bottles, they are OK with the pressure generated by the yeast and sugar. I have also used juice bottles (thicker plastic, gallon and 3 quart sizes).
Never had one blow up (yet).

If there is one that is going too slow I will swirl it a bit. Do not shake, that would get goo into the tubing.

[Hoppy]

Those valves are very likely to be leaking at the stems, losing most of your CO2. It is hard to overstate how tiny a leak it takes to deplete all of the CO2.

No one really has any control over the bubble rate with DIY CO2, nor do we need to, especially not for a 55 gallon tank. It would be very hard to get too much CO2 this way for that size tank.

[Zorfox]

Thanks Hoppy. I may just remove the exhaust and valves and see what happens. I am getting a PH change of 6.6 from 7.4 with what I have. Based on whatever the hardness level was, it calculated out to about 23ppm of CO2. Well below what I can produce at the production I've seen.

I'm still on the fence of cost versus result for a pressurized, PH managed system. It certainly is easier but is the result equal to the costs? I wouldn't know since I have never used one.

[creekbottom]

Just a question - Isn't DIY CO2 on a 55 gallon tank an insane idea?

Don't kill me for asking! It seems to me it's like bailing out the Titanic with a wine glass.

[Zorfox]

Originally Posted by creekbottom

Just a question - Isn't DIY CO2 on a 55 gallon tank an insane idea?

A pain? Yes.

Insane? Not if your willing to tinker (and quite honestly it's already getting old lol).

I'm obviously no expert but this is how I see it. The amount of CO2 produced is a ratio of yeast to food assuming the conditions are correct. So one could easily construct a system large enough to overdose a 55 gallon. So the only disadvantage I see is the inability to meter CO2 based on PH. Maintaining a stable environment is in my opinion the "hallmark" off a good Eco-system. So the first disposable $200 will most likely head in the direction of a pressurized metered system. However, since I don't have the tooth fairy's phone number my DYI will have to suffice.

[Diana]

On my larger tanks I run 2 or more bottles with refill staggered so the CO2 supply is more stable. It is still probably pretty low, but not as bad as running just one bottle.

If I get Genie's phone number I will pass it on (after she grants me my 3 wishes) ;-)