I set my aquarium up two months ago, leaving it to cycle for just over a month. In the tank whilst it was cycling I had only drift wood, plants and a plant in a terracotta pot. After ammonia and nitrite levels went up and then came back down I was told the tank was cycled so I purchased; 1 Bristlenose Catfish, 4 Neon Tetras, 4 Cherry Barbs and 2 Dwarf Gouramis.
The aquarium I have is an AquaNano30 and it holds roughly 22L. The trouble I am having is that my ammonia has spiked and (what I think is a result from that) all the little fish are gasping at the top (Everything except the Gouramis (including the catfish) are spending a lot of time near the surface gasping). I did a 30% water change when this first happened, then they seemed to be okay for half a day, but then they went back to gasping at the top. My next thought was that the plants in the evening where taking oxygen out of the water and so I removed two of the three and this seemed to help for a little while too. However they are at the top gasping again. The Nitrite has been 0 every time I have checked the ammonia.
The fish do not have red gills, they seem capable of every so often just swimming around the tank normally but then they rush to the top and start gasping. I have used some Stability by Seachem when I did a water change today, and it hasn't made too much of a difference. My ammonia has come down a bit after the water change to 2 (which is still dangerously high, but it was at 4).
I do not have any idea what to do really to help these little guys. Any suggestions?
My filter is on high now (I had it on low before) but it makes it hard for the fish to gasp at the top as they get moved around, so I'm not sure if its a good idea having it on high. Could I have broken the water cycle by chance when I did my first water change? Another interesting point, when the light to my aquarium is off, the fish do not gasp at the top as much as when it is on.
The water conditioner I use is Safe Start by VitaPet. I live in Adelaide and so have been using Adelaide tap water. Should I be using PuraTap water?
How often should I be doing water changes? Two weeks ago I did a 25% change, but it was no better the next day so I did a 50% change. I did a 50% change today and still a few hours later they're gasping at the top.
I can't think of any other additional information, so I hope this is enough for people to help troubleshoot for me.