i just received my 4 loaches a while ago and they are in a 10gal quarantine for now and will go into my 90gallon,..
these are cold water guys,. and the amount of activity they are displaying in the 10 makes me wonder about the 90 if its big enough,.. and mine are babies at 4 inches,.. i would not think they would like being in a 20, for life,..
also they play so much that 1 would be a shame,... to itself as well as you,..
large tank, large critter,.. and fast a lightning,..lol love to swim,.. at it all day and all night,.. in,.... out,.... around,.... up,... down,.... sideways,..... they are fun, but please go get them a large tank,.. and love them,..
or they will be sorry,...