Hydrocyanide:
that is my video.... I ran duel 3/4"overflow T-ing to 1 inch to the sump... It flowed 400 to 450 GPH. If i would make it again I would T it to 1-1/2" to the sump and it would have gotten more flow,, maybe 600 to 700 GPH ... Yes the shorter you make the overflow the less...