Upgrading my off low box and pump

So with my current setup I have a fluval on my 90g tank with a 20g sump also. The sump was off my 20g reef I used to have so I definitely don't have enough flow to the sump it needs to be upgraded.

Currently I have an eshopps pf-300 (300gph) and a rio 2100+ which is rated at 692 GPH

I used a 1/2 jug to see how fast my overflow works and it took 9.9 seconds to fill it up which works out to 182 GPH

I can't believe the pump only gets 200gph to the overflow that's more than enough for my 20 setup but obviously not for my 90g!!

I'm shooting for 630g and I need a pump that will get that to the tank.

What pump should I get? Brand and size to get 630gph

Rio says that their 2100+ will pump 200gph with 6ft of head pressure so my head pressure must be 6ft.

 

Reeflo blowhole 850. 3 settings on it 460/660/850

 

I think the blowhole 1100 would be better. Those pumps aren't very expensive! Do they attach with PVC? I want to split my return line in the tank to two separate returns. To reduce flow I'm sure 700 GPH causes a lot of turbulence and I don't wanna be blowing my seahorses around too much

 

Yep, youll need 1in thread by 1in female. Now, fyi what ever volume they say is true. They are not a centrifical pump, they are pd(positive displacement) pumps which means that is the gph they will put out at 26ft. Lots of flow

 

Can I plump it over the side of the sump? It's full of water I can't drill it. Do I have to prime the line if I do? What happens in a power outage?

 

You need to drill it so that you can achieve constant prime for that pump. Its a great pump

 

Can I drill it without emptying all the water? Maybe if I empty the last chamber then drill it and clean up and fill it back up? That may be the easiest? How low does the hole have to be?

Or I was thinking if I ran it over the top I could put a T in at the highest point then ill attach a smaller pump to the top of the T. Then, Ill connect both pumps to an apex and have a pump startup sequence program that will turn the smaller pump on long enough to prime the line and then turn the return pump on. Same as dumping water in to prime it.

I do have heat issues so I want to use the reeflo but I don't want to restart my sump in order to drill the tank.