Originally Posted by J.Mcpeak
120 gallons? Because it should be!
At a guess, the plec is creating enough ammonia to kill the bacteria responsible for utilising nitrite. Very small amounts of free ammonia are needed to kill it off.
Most likely overstocked. Just with one fish...........
Have you got any pictures?
The only lido 120 I can find seems to suggest 120 litres, which is not nearly enough for any fish at 11" let alone a particularly messy one such as your catfish.
(That is slightly presumptuous of me because your initial statement lacks a lot of facts, timescale, parameters, volumes, original stock density etc. etc.)
Hi, sorry about the lack of information. I rescued the plec from a very very small tank. It has grown since i put it in the new tank. I had the tank set to 26 degrees and had it fishless for 1 month with real plants on wood and and based. After a month with the plec i noticed we had gained snails and planeria worms... i introduced a betta and clown loaches and danios, thinking these would reduce the snails and worms. But within a fortnight the danios had signs of fin rot and the loaches become ill. The amonia and ph had rocketed and a strange smell appeared. I did water changes and fin rot treatment, but within 2 days all danios died, loaches had died. I did an emergency tank and moved the betta and pleco. I emptied the tank and removed all substrate and filters and full clean. I put in new gravel and plastic plants and new filters. Because it was a temporary tank, that was holding the two fish and put them back into the rebuilt tank. Currently amonia is 0.5 and ph is 7.5 and nitrites is very high 5 plus, but nitrates is very low and hardley showing. Temp is 25.6 c.