Picture of the entire aquarium?
What are the aquarium dimensions (length x width x height)?
What is the ammonia, nitrite, nitrate and pH of the aquarium water?
How often and how do you clean the filter?
What is the GH
(general hardness) and KH
(carbonate hardness) of your water supply?
This information can usually be obtained from your water supply company's website or by telephoning them. If they can't help you, take a glass full of tap water to the local pet shop and get them to test it for you. Write the results down (in numbers) when they do the tests. And ask them what the results are in (eg: ppm
, dGH, or something else).
When you do water changes, do you gravel clean the substrate?
Do you dechlorinate the new water before adding it to the tank?
Do you have driftwood and algae in the tank?
If you have big cichlids, you might have high nitrate levels, which will kill catfish very quickly. I would do a bigger (50-75%) water change and try to do them each week (say every Saturday). You should gravel clean the substrate every time you do a water change.
Make sure any new water is free of chlorine/ chloramine before it's added to the tank.
Established biologial filters should be cleaned at least once a month. If they contain sponges and other filter media/ materials, squeeze the media out in a bucket of tank water and re-use the media. Tip the bucket of dirty water on the lawn.
Rainbowfish need plenty of plant matter in their diet and at least 50% of their diet should be plant based. You can grow soft leaf plants in the tank like Duckweed and Ambulia, and feed them vege flakes or marine algae (available from Asia supermarkets or the Asian food section in normal supermarkets). The marine algae can be bought in a dried or frozen form. Frozen is my preferred choice but either is fine.