OK, like an idiot, I have been avoiding figuring out the flow for the 12 foot tank. I did, however talk to the guys from panta rhei about a new product they are working on and it would have been perfect but, spending $1400 on flow for a 140 gallon tank seems a bit excessive.
I generally, on a mixed reef, shoot for 25X flow but avoiding dead spots is really more important in my experience.
I thought about an over the edge closed loop. I like closed loops but maintenance on them is tough. Especially with long runs of pvc to clean out.
I have used the jebao non-controlled 528gph units before and had good luck with them. They are small, cheap and quiet. I can buy extras to keep on hand for maintenance and in case one fails. I thought about two at each end and three along the back wall about two feet apart in the middle of the tank. I can still get dealer pricing on these. That's about 22-25x turnover plus the return pump which will be another 5x.
No pump I have can work on 3/4" glass. I have had terrible luck with the MP pumps and they are just way too powerful for my needs so turning down a $400-600 pump is just silly. Same goes for my beloved Tunze power heads. If they are strong enough to hold on the glass, they are $$$ and would have to be turned down to avoid locally ridiculous currents.
Any thoughts on this? Remember the tank is only 18.5" tall and 16" front to back.
I have to do something pretty quickly.