120 gal tank with plants, cories, platys, mollies, barbs and gouramis. Everything seemed fine until a couple of days ago when i found a barb has died. We have been testing for ammonia and nitrites regularly and both are at 0. Between yesterday and this morning we have lost a gourami, a catfish and 4 cories. I just retested water and the results are:
Ph 7.1
Ammonia 0
Nitrite 0
Nitrate 160
We have a CO2 supplementation to liwer the ph because our water is naturally at above 8
Obviously nitrates are astronomical which surprised me but could that be killing the fish? It explains the algae problems we've had lately. I am doing a 50% water change right now but is there anything else i can do? I am surprised the cories died but not mollies. They are so hardy.
Ph 7.1
Ammonia 0
Nitrite 0
Nitrate 160
We have a CO2 supplementation to liwer the ph because our water is naturally at above 8
Obviously nitrates are astronomical which surprised me but could that be killing the fish? It explains the algae problems we've had lately. I am doing a 50% water change right now but is there anything else i can do? I am surprised the cories died but not mollies. They are so hardy.