Pump for a 90g tank

bobyboy · Nov 22, 2015

Looking for some opinions on pumps for a 90g tank with a 40B sump. The sump will be directly below the tank about 4' of head. The return pump is going to feed a manifold that will have 4 outlets plus the straight through return. The outlets will be stepped down to help increase pressure with 2 of them stepping down 0.25"-0.50" and the other 2 stepping down 0.75"-1". One of the larger outlets will feed a chiller with the second being capped for future use. The 2 smaller ones will feed a nitrate filter while the other feeds an algae scrubber.

The 2 pumps I have that I am debating between are the eheim 1262(900gph) or a Mag Drive 18.

First the eheim is brand new with ~48 hours use, super reliable. But with only 900gph is it enough to handle the return plus the manifold?

Now the Mag Drive 18 is double the GPH but the pump is now about 5 years old. How is the longevity of these pumps?

I also have a few other pumps, eheim 1046, maxijets 900/1200, mag drive 5; I was debating about running a seperate pump for the manifold section altogether.

Any opinions one way or the other would be great!

bobyboy · Nov 23, 2015

Update, I think I've decided to go with a 1.25" drain and a 1" return line. Is this acceptable or would a 1" drain and 3/4" return be more appropriate?
The return line would go from the tank through the top of the stand to the manifold. I've been reading different ways of connecting the pump to the line itself such as either using some kind of tube to the manifold input vs connecting it with straight PVC. Any thoughts?

dbl · Nov 23, 2015

My thoughts...As to size, you'll need to determine how much flow the chiller will require. Some are more than others and will help determine the amount needed to go through the manifold. I went with a 1" return and then stepped down to a 3/4" manifold, all hard plumbed, to feed my chiller, reactors, etc. on my manifold. (I have a 120g for reference). I ended up going with a Waveline DC12000 that I love. I do not need to run it at full power and still have plenty of flow feeding the manifold with a 1/2 hp chiller.

The benefit of the DC pumps, in my opinion, is you can easily adjust the flow. So if sized correctly (read a little larger than you may need now), and you end up adding something to your manifold in the future, you can bump it up and feed new addition.

Many ways to skin a cat.

Dorkymk3 · Nov 23, 2015

My thoughts on the Mag 18 is crazy amount of wattage and heat specially if it's being use internally submerged instead of external. DC pumps are becoming more popular now and days and affordable. As for my tanks and something suitable for your tank. A ehiem 1262 or a fluval sp4 will do the job well.