Co2 Generator Disaster

I'm sorry to hear that 

You probably know how these generators work but for anyone else reading the reaction is -
citric acid + sodium bicarbonate -> sodium citrate + CO₂ + water


I haven't used one of these generators myself and the one on here in the articles uses sugar and yeast to generate the CO2 so I've googled the acid/bicarb type and found this. Is this what you did?

All I can think of is that somehow too much acid got into the bicarb bottle and the reaction went so fast that all the contents of bottle B ended up in the tank. Have you tested the pH of the tank water? If too much CO2 got in there, the pH will be very low. If the bicarb got in the tank it will be very high.



All I can suggest is to start again. If you want more fish, do a 100% water change to remove anything in the water that killed the fish. Then add enough ammonia to give a reading of 3ppm. Test the following day for ammonia and nitrite and if they are both zero, or at least a lot lower than 3ppm ammonia, your bacteria colonies are still OK. If not, you'll need to recycle the tank before replacing the fish.
And in the meantime, test your CO2 generator on a bucket of water. That way no more fish will be at risk till you work out what happened.

I'll be honest and say something happened but I don't know what. If a lot of CO2 had been pumped into the tank, it could have gassed off by the time you found things, but the damage would have been done.

Reading up quickly on this type of set up, you put water with an acid dissolved in it (citric acid, vinegar etc) into one bottle, and water with bicarbonate dissolved in it into the other. You mentioned that the bicarb bottle was empty the following morning, but how much liquid was in bottle A compared to the amount you added yesterday? If there was a lot more liquid (the contents of bottle A + bottle B all in bottle A), that is where it went. But if there was the same amount of liquid in bottle A as you started with, the contents of bottle B have to have gone somewhere and the obvious place is the tank.

Did either of the bottles fall over during the night?


Many years ago (longer than I like to remember) I studied chemistry and did post graduate research for a couple of years. The department I was in wouldn't pay for cylinders of pure nitrogen, just almost pure nitrogen, so we had to purify it between the cylinder and our experiments. The apparatus consisted of about 9 Dreschel bottles clamped to a stand and connected with rubber tubing, and some of them were left empty to prevent the contents of one bottle getting into the next one. Would it be possible to modify your kit by having a small bottle between bottles A and B and between them and the tank?



Playing with the kit and a bucket of water is the safest thing to do. If you get it to work well in there, it should be safe to use on a tank of fish.

I have been reading up on CO2 since your first post and see that a lot of people turn the generator off overnight. Plants use CO2 during the day but not in the dark so the concentration can build up in the water.

Do you have hard or soft water? You can find this information somewhere on your water company's website. If it is soft, your KH (carbonate hardness) will also most likely be low. Carbonate buffers against changes in pH. If KH is low there is not much buffer and the pH can significantly.

I don't use CO2 and my tank is crammed with plants. I just use liquid carbon every day which seems to do the trick. Simon doesnt use CO2 either in his tank is lovely, have a look in the gallery.

Plants like anubias, java ferns and crypts are all very easy to grow. 

Simon, I contacted Dan btw. Can you let me know what else you use apart from the liquid carbon please?

Hi

I also don't use CO2, like Simon I chose easy to care plants mainly as I was a complete novice at the time and it has paid off.

Having had fish die from an unknown cause myself I can understand how upsetting it is especially when you don't know the exact cause.  I know this won't necessarily be much consolation to you at the moment but it might be worth thinking about and maybe changing some of your more demanding plants before you restock your tank.

Anne