Wooly1970
New Member
Hi all. Sorry for the lengthy post, I just wanted to give as much background as possible to my query.
I was hoping for some insight and advice on what went wrong with my recently installed CO2 system. I went back to the aquarium specialists that I bought the system from, but I think they were grasping at straws for what killed.my fish overnight. I have been running my 400 litre tank for a couple of years without too many water issues but have never been able to keep plants alive. Yesterday, I bought and installed and expensive PH controlled CO2 system which runs in line with my enhiem cartridge filter. My water stared with a PH of 7, a KH of 40, no noticeable ammonia and a NP2 of just over 0. I set the CO system to target a PH of 6.7. It got down to the target PH fairly quickly and maintained it for the next few hours before the lights switched off. The CO2 indicator bulb by then was a nice green, fish seemed happy and I went to bed feeling happy with myself. Unfortunately this morning when I first checked the tank (some 12 hours later) all of my fish bar 2 loach eels and a bristle nose catfish were dead. I re-read the water and the PH was 6.67 NO2 was 1 (possibly because I had 20 plus dead fish floating in the tank overnigh), no noticeable ammonia and the KH was 80 (which could be an anomaly with the test strips as it tested and 80 a few hours after the sample was removed from the tank). The aquarium shop after much umming and arrring finally came back to me proudly saying that they had found the issue to be the nitrates. My nitrates (NO3) are high and have always been high (140). I have always been told that the nitrates will have little affect on the fish and I can attest that fish have always been happy and healthy until I started the CO2 system. Is there some truth in the combination of NO3 and CO2 being the single cause of a almost 100% fish kill overnight or should I look elsewhere?
I was hoping for some insight and advice on what went wrong with my recently installed CO2 system. I went back to the aquarium specialists that I bought the system from, but I think they were grasping at straws for what killed.my fish overnight. I have been running my 400 litre tank for a couple of years without too many water issues but have never been able to keep plants alive. Yesterday, I bought and installed and expensive PH controlled CO2 system which runs in line with my enhiem cartridge filter. My water stared with a PH of 7, a KH of 40, no noticeable ammonia and a NP2 of just over 0. I set the CO system to target a PH of 6.7. It got down to the target PH fairly quickly and maintained it for the next few hours before the lights switched off. The CO2 indicator bulb by then was a nice green, fish seemed happy and I went to bed feeling happy with myself. Unfortunately this morning when I first checked the tank (some 12 hours later) all of my fish bar 2 loach eels and a bristle nose catfish were dead. I re-read the water and the PH was 6.67 NO2 was 1 (possibly because I had 20 plus dead fish floating in the tank overnigh), no noticeable ammonia and the KH was 80 (which could be an anomaly with the test strips as it tested and 80 a few hours after the sample was removed from the tank). The aquarium shop after much umming and arrring finally came back to me proudly saying that they had found the issue to be the nitrates. My nitrates (NO3) are high and have always been high (140). I have always been told that the nitrates will have little affect on the fish and I can attest that fish have always been happy and healthy until I started the CO2 system. Is there some truth in the combination of NO3 and CO2 being the single cause of a almost 100% fish kill overnight or should I look elsewhere?