This is a discussion on should i add more to my 29? within the Beginner Freshwater Aquarium forums, part of the Freshwater Fish and Aquariums category; -->
My 29 currently has 2 angels and an albino brisltenose pleco. Should I add anything else. I was thinking of adding some pseudomugil paskai, ...
This is not a good combination. The Pseudomugil paskai attains up to 35mm (1.30 inches) and being a slender fish (linear or pencil-shape) this is not good with angelfish. As the angelfish mature, they will easily eat linear fish which is why so many of the tetra are not suitable.
I might also wonder about the nippiness of the rainbow when placed in with the sedate angelfish with its long fins. Many otherwise peaceful fish that are small find this too tempting to pass up.
Aside from the above, in a 29g you are at max with the pair of angelfish. When they are at their expected mature size of 6 inches length with fins spanning 8 or more inches, the space will be full.
If you are only adding this one more species of fish, then I would put as many as you feel your tank will handle, with corys the more the merrier. I went with emerald cats (very similar) and started with 6 in mind, ended up with 9 (at my max now) and I have already seen them patrolling the bottom in one big group quite often, after only two days in the tank.
I haven't done the math, but it looks like Byron has, 9 or 10 would be ideal.
A quick thought regarding hitting the "minimum" recommended number of shoaling fish. Aim for a couple more than minimum so that if you end up with some loss you don't have too few... not that we plan for losses but it happens.