Originally Posted by JonnyJ2312
It's 48 litres, don't know why it said gallons in my log. Yes still have 5 barbs and 3 tetras
That is roughly 12 gallons. I suggest a larger tank for the fish you have. Yes, you may think they are fine now, but they are not really. Fish grow, and they grow continually. The tank size impacts their growth in two ways, physical space and water quality.
The physical space limits the fish's activity be it swimming or interaction, and shoaling fish like all barbs and tetras need groups of their own species because of their inherent interactions. The small tank means the water quality deteriorates much faster, and this is impacted even more by the physical issue. The fish release waste and the smaller the water volume the greater impact this has; but fish also release pheromones and allomones, and the smaller the space the more stress which means the more pheromones/allomones so these build up even faster, causing more stress...and so on.
If you are interested in finding out more about this, read this article: http://www.tropicalfishkeeping.com/f...um-fish-98852/
In the profile of the Tiger Barb and the Serpae Tetra, it mentions the minimum number in the group, and the minimum tank size. These numbers were not dreamed up by someone, they have scientific basis.
Hope this helps the understanding.