The big I am noticing from the amazon postings for the DCS-9000 and the DCT-8000 is about a 2.3 ft increase in head pressure and roughly a 200 gallon increase in gph flow. Oh and it cost $13 more. For that cost I would go 9ooo. BUT that is just my two cents.
@Russ265 Didn't we figure out you actually weren't too far away from 4x-5x once head loss was figured in? (I may be blending threads tho...)
4x in my recommendation is actual flow rate - actual flow measured with a container and timer, or estimated using your actual plumbing setup and the manufacturer's flow curve or a head loss calculator - not the pump's rating.
For example, an 1800 GPH rated QuietOne could only be expected to deliver around 1100 GPH or less under real circumstances. A Mag 7 (700 GPH) only around 400GPH.
A Dolphin 6250 could be counted on for no more than 5400 GPH in a similar real world deployment. Maybe no more than 3000 GPH or so if you're bringing water up from a basement, for example. Quite possibly a lot less, depending on the actual plumbing. Along with distance, fittings all lower flow - especially angle fittings.
That's approximately 24" cubed, or about 60 gallons....maybe another 15 gallons in the sump.....probably 75 gallons or so once live rock, etc is accounted for.
75 * 2 = 150 GPH
75 * 4 = 300 GPH
More than 450 GPH of actual flow would be more or less a waste and can even cause problems.
As mentioned already, your plumbing is significant. Height of the return plumbing is the most significant if you aren't doing anything crazy with your return.
Assuming your return is five feet off the ground (1.5 meters) anything from a Mag 3 to a Mag 7 ($70-$90) or a QuietOne 2200 ($60) would work...just for reference. These are all quiet and bulletproof - I'm not sold on DC pumps for return.
For Jebao, my guess is that a 2000 ($63) or 4000 ($75) should be adequate, but I can't find a published performance curve for them...if you can find one, use it rather than guessing.
