Return pump too big?

[Molli]

The very first time I bought equipment for my marine tank was at the recent Marine Depot sidewalk sale. I was hunting around for a return pump when I ran into a friend from my planted tank club. I asked him for advice and he told me to get the biggest pump I could find. So I put down the little 350gph I'd been carrying around and picked up a gen-x pcx 40 with a gph of 1190.
I'm worried this is way too much pump for my 75g with 30g sump. I've read I can put a gate valve on the line going out of the pump to throttle it down if I'm right, I'd just like some input on whether it actually is too large or I'm just stressing over nothing. I'd prefer not to create the 'sand storm vortex of doom' my first time around. :afraid:

 

[5ft24]

You can throttle it down, but it's better to put the ball valve on the inlet of the pump if possible...
My 180G tank with a 75G sump was running 3900GPH wide open! no sand storms etc...

 

[Molli]

The inlet? really? I was under the assumption that you should never restrict a pumps intake, as it makes it so much harder on the pump. Or maybe I misunderstood..

 

[rayray]

Its too big if you just plug it in and run full open, but its a good pump so use it.

Most 75g tanks have a 1inch drain that pulls ~350 gallons per hour down to you sump. Thats good enough as you only need 3-5x per hour the dt volume of flow through the sump (225-375gph). So your return line needs to return that much accounting for head loss.

i suggest you do NOT restrict the inlet (connection to the sump) or the output. Instead, split the output with a T and put a ball valve to control how much is diverted from the display. run that branch to your chiller/UV or any reactors back to the sump.

 

[Molli]

My tank isn't drilled.. yet. I'm planning on doing the BeanAnimal system - http://reefcentral.com/forums/showthread.php?t=1310585

Since each of the drain pipes will have a ball valve I'm guessing I can make it do whatever gph I want, right?

Also, I have no uv or chiller, just a hang on calcium reactor, that I'm assuming I can't plumb to the return pump. Would it be harmful or wasteful or whatever just to make the T you suggest dump back into the sump? I could always give it a purpose later I suppose.

Thank you so much guys for the input so far. I read a lot, but it seems the more I read the less I know.

 

[Bouncingsoul393]

For the type of setup you're planning I'd just sell that gen-x you got and go back to your original idea of something submersible in the 350-450 gph range after around 4ft. of head pressure. Keep it simple, it's really a waste IMO to mess with plumbing that you don't need and waste electricity by running a pump that you have to throttle back half way with a ball valve. And ya, ball valves should always go on the output.

 

[JOSE CASAS]

Its too big if you just plug it in and run full open, but its a good pump so use it.

Most 75g tanks have a 1inch drain that pulls ~350 gallons per hour down to you sump. Thats good enough as you only need 3-5x per hour the dt volume of flow through the sump (225-375gph). So your return line needs to return that much accounting for head loss.

i suggest you do NOT restrict the inlet (connection to the sump) or the output. Instead, split the output with a T and put a ball valve to control how much is diverted from the display. run that branch to your chiller/UV or any reactors back to the sump.

Ditto or make a manifold to run your gfo reactor or carbon, calcium reactor ect etc.

 

[rayray]

Thats a very safe drain setup! drawbacks include needing a lot of space behind the tank, and more tweaking/more chances of user error. But if i upgrade yet again, i would use something like that just for the coast-to-coast calfo overflow.

i used to have a75g tank, and imo i think more than one 1.5 inch drain is too much sump flow, not enough time for the skimmer, fuge, etc. The T return could go to a phosban reactor, biopellets... you have the power in that pump to do whatever.

 

[Molli]

i used to have a75g tank, and imo i think more than one 1.5 inch drain is too much sump flow, not enough time for the skimmer, fuge, etc. The T return could go to a phosban reactor, biopellets... you have the power in that pump to do whatever.

That was another worry, since I'm planning a refugium in my sump, and I know too much flow through it will not be good.

 

[rayray]

It seems like safety is a priority for you, if so simplicity & redundancy are key, at the cost of efficiency an performance.

Then you should consider 2 pumps at ~300gph each. When you start adding chillers, reactors, etc your pump collection will grow.

Imagine if you have have two1.5 inch drains working & the power goes out. Better keep the sump volume low or else...flood. If you run with a low sump, imagine your ATO fails on vacation...

 

[Molli]

According to the reef central sump volume calc, with the drains 2" underwater I'll need 7.5 gallons of room in the sump to prevent a flood. My sump is 30 gallons, and I read that no baffle in the sump should exceed 2/3's of the sumps volume, which will give me a little over a third of the sumps total volume for a flood. I have a 2.5 gallon margin of error.

This sounds great to me, but it's all theory since as I've said before I haven't even gotten started yet, and I welcome all input from you more experienced hobbyists

 

[smalltime]

Ditto or make a manifold to run your gfo reactor or carbon, calcium reactor ect etc.

agreed