Help choosing return pump size

[NewbReefer316]

First off, sorry if this isn't in the correct area.

I am setting up my first tank, a 90g w/ 20g sump, and ordered a jebao dct-8000 off the advice of someone who helped me order some lights.

I got the pump in and it just seems like it's too much for my setup, I haven't installed it yet because I'm still a good way away from even adding water. I've got conflicting information since ordering it but most say that it's too much and the 6000 or even 4000 size would be better for me.

How do I figure out where to start. I don't mind going larger than what I need giving room to grow but I do realize that you can only turn the pumps down so much which could mess with the balance of the drain/pump system.

[TimeConsumer]

I can't comment much on how much you can turn down a DC pump via the controller without issues. But I can tell you that installing a ball or gate valve on the output you can control the flow without any harm to the pump. You are simply increasing the head pressure to reduce flow. I used a Mag 9 (950 GPH) on a 75g turned down to maybe 300 GPH with a ball valve for years with zero issues.

So with a huge pump like that you could probably run it on a low setting and use a valve just fine. But I would probably return it for a smaller pump if I were you. Why have more pump than you need?

[Mark Bianco]

Before you return the pump there are several things to consider.

General rule of thumb what a lot of people use for return flow is 3 to 10 times the tank total volume per hour.

First off what type of return are you using on the tank and what is the capacity of it? In other words if your drain system can only handle X number of gallons per hour then that will be your limit as the most you run into your tank. As suggested above a gate or ball valve on the output is a great way to control the flow rate. Pumps run more efficiently when you partially restrict the flow.

If you plan on doing corals sometime then you will want to invest in a skimmer some skimmers you can use your return pump to feed the skimmer by adding a manifold and another valve. This is good and could be bad as it will save space in your sump that's good, but the bad is some people think its putting all your eggs in one basket is bad. The truth of the matter is if your return pump dies then the skimmer running on a separate pump is doing you no good...

IMHO; I would keep the one you have as long as you have room in your sump for it.

Hope the above helps.

[ca1ore]

I've not used a Jebao return pump, but assuming the model number corresponds with liters per hour, then 8000 is far more than you'll need for a 90. I'd think 2000 would be more like it. Perhaps the controller can ratchet down that much, but I think if it were me I would swap it out for a smaller model. Depending upon your setup you will lose some flow to head pressure.

[scuzy]

I run a dc6000 on my 70 tech tank and i feel that's a bit too much pump. You should run the 6000 model.

[Vinny Kreyling]

You can drop the speed of a DC pump WAY down.
My DC 12,000 goes low enough so I get no flow because of head pressure.
Wattage increases or drops with each position of the controller.
Keep it - if you want to get a smaller model & keep this for a back up.
My thoughts are you will be fine.

[DrPheel]

I got a dc-6000 on a 70g cube w/ 25g sump. I have it running at 70% and the return line manifolds in a BRS dual reactor and a phosban 150.

I rather have a big pump running at half its power than a small one running full blast all the time. Those DC pumps are magic !