water height / weir / pump flow

[reeferfulton]

internal tank overflow .

no there is no real way of adjusting the teeth height. i made the glass over flow area 22.5 inches tall .
then covered that in acyrilic right to the top of the tank 25"

with teeth cut down from top to the 22.5 inch glass .

Then i added a 1/2 peice of acyrilic all the way around to effectively raise the start of the teeth to 23" ..

How do other people do this ..
I was thinking one day i would upgrade my return pump to a higher flow. but then was stumped , as this would effect my overflow into the wier