I currently own a 55-gallon tank with a 225 gph filter (with measures taken to neutralize the strength of the water flow) that houses seven firebelly toads (six Oriental, one European). For many reasons I won't bother to explain, I had to "refresh" the tank; the toads were in a container for a couple days while I scrubbed clean the tank, hand rinsed all the gravel etc etc etc and then put it all back together. It's doing well, though most my plants I had in there died. I have plans to replace them already.

This time around, I decided to change things up and I re-set up the cage in such a way that it highlights the underwater section in addition to the land. With my filter and the regular water changes, I know that it would be entirely feasible to house ghost shrimp and rosy minnows, both of which are very hardy (I have successfully kept the minnows, I have never tried ghost shrimp). My question is, what other aquatic creatures can I keep in there as well? The water is about three inches deep, though to a limited extent I have the ability to make it deeper (to four, maybe five inches. Any more and I'd have to take large measures to arrange the land area).

I've heard that pleco would do well. I do have another tank (also 55-gallon) just for fish that I will be setting up very soon, so any fish that display adverse reaction or outgrow the tank (such as pleco) would be moved to that. I am perfectly fine with experimenting.