Some Questions about flow

[follow3]

Hey All,

How many times per hour should the water change or turn over or whatever the term?

I am thinking of getting a new pump and want to get a good one.
I have a 40 gal. breeder with a 29 gal. sump. I am thinking of getting a Mag Drive. What do Y'all think of them? What size do you recomend? Is it better to get a larger pump and use a valve to control the flow?

What do you think of SCWD's. Are they any good for making random flow?

Any input would be appreciated!!!

 

[frankienutts]

mag pumps are great,you should go 1 size bigger than you want and cut the flow back till its just right.I think I read somewher that not pumping at full speed incresses the life of the pump.SCWD's are very good at makeing randomflow but restrict the flow out put from your pump.

Good luck