Just curious how many Pristella Tetra can live comfortably in a 20 gallon tall? I have tried researching it but cannot seem to find answers.
Did I say "1-fish-per-gallon"? Too early this morning --- that's 1"-per-gallon!At 1-fish-per-gallon, you're looking at 11, but with good filtration & lots of live plants, you could have as many as 20, (more if you used a large sump), since they are healthier in a larger group, and provided that your planting leaves them at least 1 long space to swim. And, of course that would be tetras only, with snails for clean up. I love big schools of tetras! They can put me in a trance state of relaxation; add a little trance music... But, you should really add fish in small groups, ( say 3-4 at a time, waiting a couple of weeks between additions), as your nitrogen cycle will have to adjust to each new bio-load. I would go for 15, with good filtration & live plants, (lots), if you don't have a 2nd tank set up or you're not running a sump. To go higher, you would do best to have a 2nd tank & increase 2 at a time, (maximum 20), watching for ammonia/nitrite spikes that don't go away in 24 hours --- means you have too many fish & need to put the last addition in your 2nd tank. I don't believe in losing fish, so I play very conservative when it comes to stocking limits.