you can have a fair few in a 2 ft tank. they get about 13 cm (is as large ive seen them) but are very slender. they need lots of hiding spaces, and need to be in a group. they are naturally shy fish.
pH 6 - about 7.5 is good, but they can tolerate a wider range.
they will eat left over food at the bottom and algae tablets. they are good scavengers.
the sand should be deep enough for them to burrow in (they will actually sit in the sand).
but if you have sand put lots of plants in there too :bounce:
for algae eating you could get some ottos.
khulis will be useless at eating algae off the glass.