Hey guys would appreciate the help.. i see tanks that come with built in overflow sometimes two overflows an sometimes predrilled holes? what is this for? and in what situations is this good/bad? i always had fish tanks but 55gal or less lookin to buy a 125gallon or 135 an no clue what this is?!
love both of these fish wanted to know if i buy them both as babies can you mix Tiger oscars and electric blue jack demseys in same tank?
was looking to get 75 or 90 gallon.
thanks for the help!