questions about DIY overflow and sump

[Kevccoy]

I am thinking about a DIY sump and overflow, I have 2 emporer400 filters now and willing to keep them, or at least 1. just want some extra filtration and water volume. my questions are if i do the PVC overflow what size pipe should i use, and in the sump what size pump would work best .
I have a 75 gallon tank and a 20 gallon tank to use as a sump.
any help with sizing would be great.
thanx

 

[prcdslnc13]

what size pump are you going to be using for a return pump? 1" can handle 600gphish if its unrestricted. and you always want your overflows to be able to outrun your pump.

 

[davdev]

I have a 75 gallon tank, and I have setup two overflows each with 1" pvc. I can get by with one, but I put in the second as a redundancy. I have a Quietone 2200 pump that does about 400gph. I find this to be sufficient. I have seen people recommend the Quietone 3000, but I honestly don't think my overflow would keep up.

 

[Kevccoy]

would it be ok to have 2-3/4" overflows instead of 1-1"?
and thinking of the quiet one 2200 as stated someone above is using.