Looking for fish suggestions

[Herpin Man]

I am in the process of building a large paludarium. The water area will be about 4' by 8' by 2' deep. I plan on having some Nigerian clawed frogs. This species reaches about 2" as adults. I need to figure out what type of fish I can safely keep with the frogs. I am thinking either something small, that is fast enough so that the frogs do not catch them, or something that is too large for the frogs, but won't pick on them. I'd rather not have goldfish. If the fish are prolific breeders, that is a definite plus. So are bright colors, so that I can see the fish; the aquatic portion of the enclosure does not have transparent sides. Water temps will generally be in the mid 70's.
Any suggestions?

 

[TekFish]

Could you give the water parameters of your tank? pH? gH? Things like that? It would give us a much better idea of what can go in your tank. Thanks.

 

[Herpin Man]

I really don't know what the water parameters will be. It is not set up yet. It will be more of a pond than an aquarium- it is a wooden structure with a pond liner. There will be plants and driftwood. A pond filter will be used. Since it will be designed for frogs, I think water parameters will be somewhat flexible.