Say I wanted to set up something along the lines of a 30g long prop tank plumbed into my existing 75g system, would I add a 2nd return pump for it or upgrade the existing pump to a higher GPH and split the flow?
If you could work ou the gravity drains -- I'd try to drain to the second tank first then let it drain to the main sump and pump return to the main.
If you can't I'd probably put a tee in my main return and divert some flw to the second tank again letting it drain to the sump. In either case make sure you have enough overflow space in the sump to handle the extra from the second tank.
I've got both setups on my system... Some of the extra tanks have their own dedicated pumps, some split the flow among a few tanks from one pump, both work fine...
Quite often having 2 moderate flow pumps is less electricity draw then 1 bigger pump of the combined flow of the 2 moderate pumps, and in that case, I'd make the argument that having multiple moderate/low flow pumps is more efficient...
I agree that in this case 2 pumps are better an most likely more efficient then one larger one. i was suggesting trying to use your existing pump only, but if you need to upgrade, it's a good idea to go with two.
