Trying to pick the right return pump

[ElGuappo]

Originally Posted by BlueTang<3

Well some people are hardcore with that saying that not to do more then the skimmer can handle. I am more of the biggest you can fit then throttle it back

+1
the more flow you can get here means fewer powerheadsd in the tank. at least IMO

[wingedfish]

I have a 75G with 30G sump, herbie with 2 1" bulkheads. I run a mag 9.5 full out. that would likely be 7-800gph. seems to work fine.

[viperfish]

A high flow rate will mean you can branch off the return and drive other things such as media reactors. I agree with BlueTang<3 about throttling back a larger than needed pump, it allows you control over the flow. I'm a huge believer in keeping the flow below the rate the skimmer can process, you don't want water ripping through the sump and back in the tank without skimming/cleaning first.

[Murminator]

Originally Posted by wingedfish

I have a 75G with 30G sump, herbie with 2 1" bulkheads. I run a mag 9.5 full out. that would likely be 7-800gph. seems to work fine.

I have the same set up on my 90G works good

[xblade]

Thnx for all the input guys...I'm thinking, go big.
I'll shoot for about 800 gph at 5 foot head.
What pumps would you recomend?(in the $200 or less catagory)

Should be getting tank back soon.And then the fun starts.

[sphelps]

When estimating head pressure you should multiply the vertical height by at least 1.5 to take friction and minnor losses into consideration. A factor of 2 is typically what I go with because over time the pipes become dirty and rough which adds significant friction.

So if you have 4 feet from sump level to display level you should estimate 6-8 feet of head pressure.

[sphelps]

Originally Posted by ElGuappo

+1
the more flow you can get here means fewer powerheadsd in the tank. at least IMO

+2
I'm also a fan of large turnover, a 75 gallon with that kind of drain can handle a very large turnover without causing problems relating to noise and micro bubbles. The only source of bubble problems would be from the skimmer, if the skimmer releases a lot of micro bubbles a higher flow rate through the sump may cause them to bypass bubble traps/baffles. However proper design and sump layout can avoid this quite easily, and choosing a skimmer which doesn't exhaust a large amount of bubbles is always a good idea. Skimmers which use diffuser plates and have larger diameter bodies typically do better at containing air bubbles.

I'd aim for at least 1000gph turnover, if you can go a little higher and hit a 15x rate at 1125gph even better. However hitting such a number isn't always desirable as typically you need to run larger external pumps which can create more noise. Usually you have to spend quite a bit to get a quiet pump capable of such a flow rate so this whole pump selection may be based on your budget. What is your budget?