Variable flow return pump

[ckyuv]

I recently ordered a new tank, and with it I ordered the ecotech wavemakers and figured I’d get the vectra s2 pump since it has the same controller/modes the mp40s have and I assume I can make it run at different speeds and make waves and whatever. 
 

looking at the Red Sea tanks, they have a valve on the overflow drain that I guess is made for noise/flow. My question is, can you do a variable speed return pump with a sump/overflow or is that gona mess with everything in the sump? I have not messed with a tank in a bit but I’m vaguely remembering that’s not a good idea now after buying it. Wondering if I should have maybe spent $100 on a sicce return pump vs 350 on one I can control since changing the speeds isn’t a thing it seems like.  

[+Jimbo662]

You'll be good with a variable speed pump. You start with the valve most of the way open. Once you figure out how much water you want to turn over you start closing the valve a tiny bit at a time. Wait about 15 min and adjust again. Once you no long hear the waterfall going into the overflow box you're set.

One thing to think about, the more water you have going into the overflow the more water will be going through the filter socks or whatever you choose for your media. The more water the harder it is to silence that area.