Which fish are you talking about?I almost forgot........
I've got a planted 12 gal with Variatus at room temp. They are also beautiful fish for beginners.
I have 8 in a 70 gal tank. In summer I put a trio in a 12 gal tank; daily 20% water changes and a good water current. Managed to observe breeding behaviour. I think that young wl will do ok in a small tank as long as their water parameters are observed.