Two return pumps instead of one?

[Reese]

I have a 75 gallon tank with a wet/dry below. It's going to be a FOWLR. I was going to use a submersible pump and split the return. But, I already have a RIO 1700 (642 gph) and a CAP 1800 (650 gph). From the top of the tank to the bottom of the sump is just over 4'. And the tank is not drilled. I have an overflow box.

Does that sound sufficient or should I bite the bullet and buy yet another pump like a rio 3100 or a mag 9.5 and split the return?...

[Brenden]

What GPH is the overflow box rated? Use one of your pumps for the overflow and the other for a closed loop. The overflow box will probably not handle both pumps.

[Reese]

Sorry, I did a quick search and didn't find anything yet. What kind of outlet is used in a closed loop? Do I need a separate overflow box? Where do I find out what my overflow is rated for? It came with my wet/dry (rated for up to a 90 gallon tank).

Also I was planning on using a separate small pump to circulate the water in the sump through a UV filter and back into the sump. At what depth should I have the water flow back into sump? I mean should I keep it low or is that going to be a problem kicking stuff up?

Thanks.

[Brenden]

Closed loop just eliminates PH's. It just takes water out of the tank and puts in back in where you want it for flow. You can probably find your over flow specs at liveaquaria or just post what it is here. Someone probably has one.

At what depth should I have the water flow back into sump? I mean should I keep it low or is that going to be a problem kicking stuff up?

What not just make a DIY spraybar? Cheap and easy and will eliminate "stirring stuff up" and will help oxygen exchange.

[natman2]

If your overflow box has only one drain and it is 1 inch in diameter the box is a 600GPH overflow and it will only handle one of your pumps.

If it has two drains 1 inch diameter it is a 1200 GPH box. Then considering the head it will probably handle both pumps.

If the later is the case make sure your OFB will not loose siphon if only one of the pumps is functioning. Start the overflow with both pumps. Make sure no air is trapped in the U tube. Then shut down one pump. If air starts to collect in the U tube then it will eventually loose siphon.

If one of the pumps fails while you are not at home the box will lose siphon and the remaining functioning pump will flood the room.

[Reese]

Thanks Brian.

The spraybar will work. Perfect.

I'll have to think about doing a closed loop. I guess I could just add another siphon tube to the overflow. But do you think that I'll get adequate flow with those two pumps working in conjunction?

[Reese]

Originally Posted by natman2

If your overflow box has only one drain and it is 1 inch in diameter the box is a 600GPH overflow and it will only handle one of your pumps.

This is the one I have. So what is my best option? If I only run one of the pumps is that going to be enough circulation?

Thanks.

[Brenden]

If a closed loop is not what you want to do I would just buy some PH's before I would add another siphon tube. This is all dependent on what your overflow is rated for. I personally think having two return pumps would be a pain. There is really no wrong or right way. I would just try to make it as simple as possible.

[natman2]

600GPH into your sump should be fine. More circualtion in the tank itself should be added however. Most shoot for 15 to 20x turn over in the tank useing power heads or spray bars .

Considering your head you may want to buy a higher flow pump for the sump. The rateings for the pumps you have are most likely without considering head or any elbows if your return is hard plumbed with PVC. With four feet of head you may be able to use both of those pumps together and the head will reduce the flow from both down to where the OFB can handle it but IMO that set up is risky and may require installing a ball valve in the return to back off the flow if its to much for your OFB

If you look on the box when buying a pump there should be a graph telling your the flow rate at various heads. In your case you want one rated for 600 GPH at four feet of head.

I would stick with one pump at that rateing due to the reasons I mentioned in my previous reply.

[fishman]

Not to high jack this, but can someone explain a closed loop and or send pics of this? I have 6 PH's in my tank and HATE them! I really want to do a closed loop as it sounds better. I have 2 overflow boxes with 1 outlet.

[Reese]

Originally Posted by fishman

Not to high jack this, but can someone explain a closed loop and or send pics of this? I have 6 PH's in my tank and HATE them! I really want to do a closed loop as it sounds better. I have 2 overflow boxes with 1 outlet.

I believe, judging by what Brenden posted and what I've since read, a closed loop is as simple as some sort of outlet (I saw one with a length of pvc with holes drilled in it) connected to an external pump. The water is then redirected directly from the pump back into the main tank in however many returns you choose.

[Reese]

oh and thanks again for all the help/ideas...