they will need something bigger, just get a cheap 50 gallon and an aquaclear for them.. they will grow into it in no time.
nice build
I left my old 90 with my ex because after my showpice fish died while i was working on the road her 3 goldfish and 2 plecos got moved in. after being in there a year there was no way they could be moved to something smaller. if you keep the water clean enough to keep them alive they are almost indestructable.