Built-in Overflow Problem

Pszemol wrote:
Is this tank purchased with overflow or you built it yourself?
Usually, tanks available at stores (Allglass, Oceanic) have
overflows properly designed to rise water above frame level.

This tank was purchased with the overflow built-in.

p.s. what pump do you use ? how much gallons/hour or litter/hour ?

The pump is a cheapo Rio 1700 (650gph).

The overflow has 12 1/4" teeth. I have to plug up 8 of them before the
water level gets above the plastic rim. My only task now is to plug them
up in a non-permanent way that isn't visible while viewing the tank.