How long have they being doing only once a month water changes? You don't want to do a large 50% change if they haven't been changing the water that often for years. The fish will go into osmotic shock.
The nitrites dropped because you did a water change. Prime detoxifies ammonia and nitrites. It does not eliminate them. Dechlorinator only remains in the water for a day or so and then is gone. By then, the chlorine or chloramines have been eliminated.
I'm curious... what are they stocked with? That's not a small tank...
300 gallon mega tank
: build in progress
75 gallon community tank
: tetras, danios, corys, platies, otos, pearl gouramis, bristlenose pleco, assassin snails, red cherry shrimp, bamboo shrimp
70 gallon growout tank: clown loaches, sailfin pleco
60 gallon goldfish tank: fancy goldfish
29 gallon frog tank
: 1 bullfrog
10 gallon and 5.5 gallon betta tanks: 1 male betta each, sometimes snails
Years, they usually do around a 35% water change and rinse the pads in aquarium water.
Originally Posted by Rocksor
OK makes sense, thanks for clarifying. God knows when my nitrites will climb back up then, I might have to dose some more prime tomorrow as im at work and wont be able to do a water change til Thursday.
Originally Posted by Lady Hobbs
3 Clown loach
Originally Posted by Brhino
1 Bala Shark
4 Tinfoil barb (juvenile)
2 Bleeding Heart Tetras
1 Silver Dollar
1 Common Pleco
1 Ruby Shark
3 Paradise fish
1 Golden Sucking Loach
1 Unknown Small Pleco (4")
The Paradise Fish are mine as I bought them before I setup my own tank, i'll be moving one of them to mine once its cycled and will probably give the other 2 away as they dont seem very happy in this tank as its full of really big fish. Ive heard keeping them together is a bad idea anyway as they'll probably end up killing each other.
I wouldn't do more than a 35% water change if that's what they have been doing monthly for the past number of years.
In order to solve their nitrate problem, I would do that much everyday for the next 7-10 days, and see what the nitrate levels are after that time frame. From that point on, you can do a big change to get it below 20ppm.
I think the nitrates should be brought down asap. Changing 10% water changes to 90% suddenly might cause a slight problem but not 35% to 50-60% and then doing another one that evening.