help with building 20g sump

I have a 55g reef tank and im using a 20g long tank and building a diy sump. I will be using a hob overflow and not drilling. But i have a few questions.

Should i use the eshopps 300 or 800?
Which return pump should i use with each box?...

 

Anyone?

 

It's usually reccomended to have about 10x your sump volume as your turnover rate so that your skimmer and whatever reactors you may be using will be effective.The eshopps 300 box should handle that much with no problem.I use one on my 40b and it has been working flawlessly for the nine months it's been in use.It would be good to choose a return pump rated higher than the overflow and control it's flow with a ball valve,that way you are in control of it.I use a sicce pump rated at 560gph and it also feeds my biopellet reactor.My return line and the line to the reactor are both controlled with ball valves.

 

Thanks for the info. Is the 560 before or after head height? Ill have about 4 ft of head. I'm wondering if I should go with a 660gph with hmax of 8.6 or 528gph pump with hmax8.5. I'm new to the whole pump thing so I'm not sure what one to go with.

 

Most pumps will include a graph that shows their output at certain heights, I'd look into those and try to match your drain rate

 

The 560gph (if I remember correctly)is before head pressure.IMO it doesn't hurt to go a bit large with your pump and dial it back with a valve,some say it actually makes the pump more efficient and does no harm.

 

I'll probably go with the 660gph then. I can always dial it down with a valve but I can't turn the pump up if it isn't enough.