TRYING to making my own sump?????

I was thinking that but the only pressure would be the gravity. guess il have to buy a pump after all. and let me ask you this whats the point in drilling i know its a lil cleaner look but what do you actually gain from it?

 

That brings me to another question??

say the pumps rated at 500gph and i get a overflow box rated for 500gph. The pump is gunna be pushing up agianst the gravity will that take away some of the pressure and i also wanna run a piece of PVC along the back of the tank with holes in it to get more water circulation. is the pressure gunna cut down on the 500gph? or should i just get a smaller overflow box and put a ball valve in the pressure side to make it do what i want?

 

Thanks i like that Eshopps ALOT better