Thanks a lot tassod!
So let me wrap my head around what you're asking. You want to run both pumps together to feed the returns to the main display tank AND to run a manifold to feed accessory equipment (GFO, Carbon, etc)? Keep in mind my top pump goes directly to the display tank. The bottom pump feeds the manifold and returns clean water to the top sump. They are two independent systems.
On to your tank. Worst case scenario you have 6' of head heigh and one pump can push ~1200 GPH. So two plumbed together may be able to double that, assuming you're using large enough piping. The tank really only needs ~5x turnover so that uses up one of the pumps capacity. The second pump would be more than enough to feed the manifold. The tricky part would be plumbing it so that if one pump quits when you're not around, the flow from the other pump doesn't take the path of least resistance and go right back into your sump through the other pump. In my original design I was going to have two return pumps in the top sump. They were both going to utilize GF check valves to ensure if one pump failed the flow from the second pump will sill go into the display tank. plus they would have union ball valves to make for easy maintenance. When it comes to the returns in the tank, I have locline valves on all of my returns so I can regulate the flow.
I have not used the reeflo's, and to be honest I think they discontinued the BH line, so I don't know what that says about their reliability. You may be better off to buy a quality single DC pump to handle the task. Think about your needs:
How much "through sump" flow do you want? I'd suggest 5x the tank volume.
How much flow does your manifold require? Many reactors are ~100-200 GPH.
Do you want to have to maintain one pump or two? One is cheaper, two means backup if one fails.
Quality check valves (still not fool proof) are ~$100 a piece, do you want that added expense?
A huge percentage of reefers use a single pump to run their systems. It just gets touchy to balance out flow to the accessory equipment. If I was feeding the skimmer off the pump, I'd have a stand alone pump to run the manifold. That type of equipment requires a consistent water height to operate at its best.
My manifold will feed a couple reactors who's flow isn't critical, hence why I have the lower pump running double duty, return to tomp sump and feeding the manifold. Just for comparison sakes: A200 (top pump, 200w) is ~3800 GPH, A100 (bottom pump, 100w) is ~2100 GPH.
I hope that helps!
Scott
The ozone generator has been one of the biggest x-factor purchases to make. There isn't a ton of material to find on them. Also, nineball uses RK2 equipment on his 1350g, and he doesn't skimp on anything. Good enough for him, good enough for me lol!
