Well, I don't know what the experts will tell you but I will say this. I've read that some hard core sps junkies have 60+ times turnover in their tanks and I thought hmmm... that sounds cool. I've had sps for a while, and they have lived and even grown a little but now with this set up I have they are thriving- bushed out more than ever before and I have been able to see growth in a short amount of time. My fish don't seem to mind it - in fact, now after adding these pumps my domino damsels are laying eggs! My tank is cleaner than ever before and all in all it looks better than ever. With my pumps on 100% I have about 50X turnover an hour. With the controler though they aren't on 100% all the time, they ramp up and down from 50% to 100% back and forth every 15 seconds. The current that this produces is quite chaotic to say the least, but I love it- my water evaporates a little faster now though due to all the surface turbulence- I have to believe that is good though, must help gas exchange a great deal.