closed loop method

[BBQHILLBILLY]

scenario:
2 1in holes drilled on bottom glass for closed loop.
will not drill more holes.
external pump 1900gph

Flow Chart

1/2 " PVC
3.5 GPM
210 GPH

3/4" PVC
6 GPM
360 GPH

1" PVC
10 GPM
600 GPH

1 1/4" PVC
20 GPM
1,200 GPH

1 1/2" PVC
30 GPM
1,800 GPH

2" PVC
60 GPM
3,600 GPH

2 1/2" PVC
100 GPM
6,000 GPH

3" PVC
175 GPM
10,500 GPH

What is the best method to plumb this closed loop?

[BBQHILLBILLY]

Im probably turning this into calculas. I probably could just add a mag 18 pump in the sump and feed the 2 1in return holes. Is there something I could get that if the power goes down I wont have 240 gallons of sw on the floor? lmk

Also The only reason I didnt want to do that was because I was going to have an ext return pump 1900 feeding the sump. thats good flow through the sump.
Now add a mag 18 flow thats a lot going through the sump/refug.
Thats why I would like to keep it separate and on a cl.

or maybe not. hmmm

I could use the holes as drains to include a water drain for water changes plumber to ext pump
and then use an two external pvc up around the back and into the tank halfway down for more water movement.

[Gseclipse02]

Putting the pump in the dump is not how a closed loop works one hole will be ur intake ur other will be ur out put will never flood unless ur pump leaks put ball valves under the bulk heads

[rrasco]

Our systems with sumps are actually open loop systems. Whereas a CL system is designed to intake water from one or more places in the tank and directly feed it back in the tank. Having CL bulkheads low in the tank, especially the bottom, makes me nervous. If you ever had a bulkhead leak or worst case a blowout, the tank would completely empty. This is why a lot of people build them into the back, but try to keep them relatively high; to limit the amount of water above the bulkhead.

[Troy Valentine]

+1 ^

CL systems were far more common years ago because power heads weren't near what they are today, but now with the incredible advancements in powerhead technology both efficiency and flow. I just cannot think of an advantage that a CL system will have over power heads. Only the added variable for another potential leak.

[BBQHILLBILLY]

I like powerheads too. Ive been using them on all the tanks I have built.
I went to cl to get the pumps out of the water. I will have 0.
And of course I wanted to try a different approach to water movement.

[Troy Valentine]

Fair enough, CL systems when done right do have a very clean look;) Someone years ago on Maast had an awesome CL, it was 3/4 or 1" PVC mounted underneath the upper trim, so you couldn't see the spray bar or intake. Very cool.... I believe it was powered by a Dolphin AMP Master.