CO2 Overload

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Zezmo

Aquarium Advice Addict
Joined
Mar 18, 2005
Messages
1,114
Location
Northern California
Even though I have kept fish in some form since I was a child. It has only been about a year that I have been interested in having plants in my aquarium. At first I was trying plants to aid my efforts to breed Dwarf Gouramis. Now it has only been about 6 months that I have been playing with DIY CO2 (high light etc). So I was pretty happy that with a little research I was able to put together a very good long lasting yeast formula. (see bottom for my recipe).
At first I was using 4x 2-liter bottles. At first I had a simple diffusion bell, and a simple ladder type diffusor. With this I was getting between 20-30ppm.
Then I went to a DIY Gravel Vac type reactor. I have this connected to the outflow of one of my Fluval 303's. The outflow of the second second one flows accross the bottom of the reactor. For a month I was getting about 35-45ppm of CO2. This seemed high, but everyone in the tank seemed ok. Then I had a few mysterious deaths. I was convinced these were caused by some unknown "toxin". I pretty much was sure it was copper. From what I have learned in the last few weeks, though I am more convinced my PH was crashing overnight due to excess CO2.
Anyways, this conviction that there was some toxin in my tap water led me to switch over to RO/DI water. I now add all my minerals back in. I mix my water in 5 gallon jugs. Each jug gets 3/4 tsp baking soda, and 2tsp of Seachem Equilibrium (GH buffer). This results in 9deg KH, and 8deg GH. PH is around 7.6.
Well at the beginning of September I got some Champaign yeast. I began using this with my normal "formula". Well all was good for a few days. But after a couple weeks my fish started acting toxified again..in fact I lost a few tetras, and all of my Gourami fry :? Well testing my water I got a KH of 7deg, and a PH of 6.2... 134ppm CO2!!!! 8O
Well I disconnected two of the bottles. And added an air pump, my powerhead has one of those venturi hookups. The Air pump is on my "night" timer. I also did my weekly PWC. The next day the water tested at KH 7deg, and PH 6.4...still 84ppm of CO2. At least the fish did not seem overly distressed...er well most of them. Well I figured I just needed to make my reactor less efficient. So I removed the airstone, just a straight airline. And I drilled a hole in the top to let out excess CO2. Well apparently this is the secret to make the reactor work even better. because the next morning all my fish were nose first against the surface and looked like they were about to die. I hate fish disasters while I'm getting ready for work. Well I disconnected all CO2 and cranked my air pump to the max. When I got home from work everyone seemed healthy..in fact, they looked better than they had in a while. With no CO2 and an air pump on for 10 hours..my water measured KH-8.5 and PH-7.4, 10.2ppm of Co2... whew.
I left it like this for a day, and then reconnected 2 bottles. I also added a "bleeder valve" to vent excess CO2. I have it set to the lowest possible setting I could, and still get bubbles all the way to the tank. This is a bubble count of 1 bub every 3-5 seconds. My water measures KH-8, and PH-7.0, CO2-24pp. Nice :lol:
Ultimately, what I have decided is that I need a PH controller, and a canister of CO2. I learned some hard lessons this last month or two. Not so much the dollar value of the fish and inverts I lost. But more their over all value to my tank. R.I.P. Big Red.... Mr Limpet... and Frankenshrimp <<salute>>


Here's the formula I use:
In each 2-liter bottle; 2 cups sugar, 1 tsp baking soda, 1tbsp Molasses, 1/4 cup protein drink mix(whey protein powder), 1.5 liters water, 1/4 tsp Yeast. I rehydrate the yeast in a separate cup with 1 tsp sugar for an hour before adding it to the main mix. Use tepid water (not warm or cold). Add the yeast and let the mix sit open over night before use. Mix at every opportunity.
 
Instead of a less efficient reactor with the same DIY CO2 source, it would be lower maintenence to keep the most efficient reactor and use less 2 liters with the same mix. I bet you'll love pressurized :)
 
I got a pressurised setup a few days ago, cuz I had so much trouble with my DIY. Gladly I didn't have any fish in the tank yet when I started out with DIY.

Nevertheless, today I don't have to worry about the right "mixture", how many bottles to use, when to exchange the bottles next, danger for my fishes, pH crashes, etc anymore! It is really worth it to invest that money.

I got a 10lb CO2 bottle for $50, the Milwaukee Regulator for $80 (incl.shipping) and had the diffusor anyway.

Exspecially with a bigger tank, like you've got, it's really, really worth it :wink: !
 
No conclusive evidence that CO2 killed the fish, DeFeKt, so please don't chastise Zezmo. That is not why we are here.

I've had Co2 levels that high a few times, and lost no fish at all.

pH swings caused ONLY by CO2 injection are significantly less stressful on fish than pH swings caused by rapid changes in carbonate hardness/buffering in the water.

Pressurized CO2 is like a dream come true after fighting with DIY.
 
Well, I can take a little grief over my learning experience. I tell you I feel nothing but bad that my poor little animals suffered through my learning. I am glad to say that since I made that last round of changes everything has been "normal". With conditions being stabilized in there once again.
 
I've just started a DIY CO2...
Tank setup:
10 gallon tank with a bunch of java fern, a bit of watersprite, and hornwort
2X25 watt incandescent lights
1 700ml DIY CO2 hooked up to the intake of my:
Aquaclear Mini

The PH rose to 6.8 from 7.0, i get about a large bubble every... 15 seconds or so. but if its not in the intake, i get a bout a bubble every 5 seconds. I dont have a CO2 tester.

SO far, everything appears to be ok. I haven't checked the PH first thing in the morning, so i dont know if it spikes at night, Do you think it would? Its a small CO2 generator... more of an experiment really.
 
pH will drop more at night, but don't worry too much about this with a small generator and passive diffusion. Try to get a KH test if you want to do experiments with reactors and multiple bottles, as it's likely all you need to derive CO2, and as Zezmo has shown it's easy to have DIY CO2 go wacky (more so in small volume). Swap out the incandescents for screw-in CFL, as the existing bulbs do little for plants. HTH
 
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