WHAT IS THE BEST WAY TO DETERMINE WHAT SIZE RETURN PUMP I NEED

[chumbucket]

I am in the process of setting up a 65 gallon tank!!! The Tank has two overflows, one in each corner of the tank. The tank deminsions are 18"d x 36"w x 24"h. I am not sure how to determine how much flow the overflows will drain so i was wondering if there was a way to determine the kind of flow i will have, and also determining what size return pump i need!!! Thanks for any input

[Gseclipse02]

i would think a mag5 would be good for that size tank

[ErikH]

what size are the overflows? The actual diameter???

[chumbucket]

what size are the overflows? The actual diameter???
The overflows each measure 9" X 5" the diameter of the overflow standpipe is 1" and the returns are 3/4 "

[ErikH]

I would go for a return that's no larger than 1200 gph. I am about 98% sure that will work. Smaller is fine.

[ErikH]

oh, that's with head loss too.

[chumbucket]

Head loss is going to be at about 5 foot from sump to top of the tank, plus i want to have a return on each side of the tank, the rest of the water movement in the tank will be provided by koralias.

[ErikH]

LOL that's gonna be alot of flow!

[Bill S]

You want to make sure you don't get more flow than a single one of your overflows can handle - or you risk flooding IF (or when...) one of the overflows gets a blockage. Snails are great at that... You can time the amount of water your overflow will drain into a bucket.

[coraline79]

Mark from MELEVS Reef, can and spoke at our last meeting, and he suggested that you cycle the tank about 8-10 times an hour with your return pump(not including your powerheads). That would put you at about 5-600gph and accounting for loss from bends and head. You could 750-900gph pump. if your water is cycling too much, I would think that your water doesn't get enough face time with the your filtration, but too little with cause build up of nutrients.

[chumbucket]

I was thinking of running a mag 9.5 and teeing it off to run a return to each side figuring with elbows, tees, and head loss i would probably be down around 600 to 650 gph. Any thoughts would be appreciated

[brewercm]

That should be fine. I was running a Dart with two 1" bulkheads, granted a little dialed back but quite a bit more output than a Mag 9.5 probably between 3 and 4 times.

[azcummins]

I'd suggest getting a 900+ gph pump and on the return line(s), put a T- fitting that returns some flow back to the sump/refugium. If you put a ball valve off the T, then you can dial in how much flow you want going to your tank.

I have a 90g and I have an Eheim 1262. Plumbing the pump straight back to the tank caused a rip current that was too much for my tank. The T-fitting approach lets me dial in how much flow I want and it can be changed if needed.

[thedude]

We size our return pumps to circulate 4-5 times the tank volume through the sump, per hour. This slower flow allows your protein skimmer to work more efficiently, cuts down on salt creep, noise, bubbles, and the heat of a bigger return pump. With your tank at 65 gallons, I would have you shoot for flow 250gph - 350 gph.

If it were my tank, I'd take a look at the eheim 1250 (little to no heat, small size). If you are going to run your return into a chiller, or other flow restrictive devices, go up to the eheim 1260 but it is a larger pump and will put out more heat.

The flow in your tank should be entirely "in-tank" ie: closed loop, tunze's, vortech's, powerheads. Your return pump is simply to take water out of the tank, into your filtration, then back up into the tank.

John

[wkada]

I have a 65g with single 1.5inch overflow and dual 3/4 inch returns. I have a "tee" off of the main return with ball valve to feed my refugium which draws off quite a bit of flow. After doing the head loss calcs, etc., I ended up getting a Mag 12. If I run it wide open , its way too much! I'd recommend a Mag 7 or 9.5 max.

[R.Allard]

IMO and you have the space and funds go with a iwaki extenal

[mariog]

I have the same dimensions of tank but with one overflow. I am using a rio 2500+ and don't have any issues. I have used a mag7 with the same results, either of them work well for me. It's about 5' of head from the pump to return.

[R.Allard]

the external wont put as much heat in the water as a internal. big plus if your runnin halides or PCs. and you can T off to run other things. just depends on what you prefer