what size return pump ?

[Shaemus]

I am planning on a 40 gallon drilled tank 1 inch bulkhead, i dont know how many gph going into the sump is there some way finding it out?
What size return pump should i have, it's alittle over 3 ft from pump to the main tank, and the pump is connected to a spray bar, and I want that to be my source of flow.

Sincerely,

Shaemus

 

[ChrisRD]

Are you looking for a submersible or external pump? Something that produces around 3X-5X turnover after losses is more than enough IME.

Generally you need to plan on something more than the return pump for circulation in the main tank.

 

[Anonymous]

Shaemus,

I was wondering the same thing recently so I tried to do a little research.
Basically, the overflow filter connected at your bulkhead (and connected tubing) gets placed right at about water surface level. This way whenever water level gets at or above the filter, it will flow via gravity down to your sump.
Since I am a newb myself, I didnt fully understand that...

With your return pump, as Chris said you want around 3-5x tank flow. So if you're running a 40 gallon setup, any return pump around 200gph should be good. I think the one inch plumbing should be fine with this.(Hopefully one of the more experienced people will confirm this for you)

 

[mr_X]

200 gallons per hour after head loss. that's like a mag5 or so...

 

[Shaemus]

thanks guys, i'm only having a fowlr so i was thinking i didn't need a lot of flow, but I will probably get a powerhead for extra flow. thank you very much.

Shaemus

 

[mr_X]

itr's not flow that you need in the display so much, it's some turnover in the sump. you do want some movement in the sump, otherwise it's going to get nasty in there.

 

[ChrisRD]

Even with a FOWLR you'll need some decent circulation in the main tank to help keep wastes suspended so they can be removed by the skimmer. This also helps keep crap from building up in the rockwork which can later lead to nuisance algae problems, nitrate issues, etc. It's also good for the fish to get some excercise... :wink:

Personally, I don't get all that concerned about flow rates through the sump. In fact, having a low flow rate through the sump can have advantages. For one it can help the sump act as a settling basin so that detritus ends up accumulating there instead of the main tank. This is easy to syphon out during water changes. It can also result in a quieter, more energy efficient setup (ie. smaller return pump, less water noises from flow through drain pipes, etc.)

 

[mr_X]

my sump gets a nasty film on the surface if i don't have the water moving pretty good.

 

[ChrisRD]

A slight film is nothing to worry about, but if it's significant, I'd be concerned about how well the skimmer is working.

High flow through a sump works well too. In that case I prefer to run a micron sock to catch the detritus as it tends to not settle out in the sump. Personally, I find this a bit more labor intensive than the occasional syphoning of settlement but if you're willing to do the extra work it can be very effective at keeping water conditions very clean.

Either way is workable which is why I don't worry about it all that much - just personal preferences IMO... :wink:

 

[Anonymous]

I'll seoncd what ChrisRD stated. I like my return to be no more than 10x tank volume per hour. My current tank is at 7x. My reasons are the same.

Less power
less noise
no micro bubble issues
things settle in the sump to be removed

 

[mr_X]

A slight film is nothing to worry about, but if it's significant, I'd be concerned about how well the skimmer is working.

:

what do you call significant? i get an accumilation of slimy bubbles in the corners of the sump area...nothing crazy, but enough to make me want to stir that up so it gets processed.
i am pulling alot of dark skimmate out of this display. if my skimmer is not functioning at 100%...where is all of this gunk coming from?
i have 6 fish in a 300+- gallon system 8O

 

[ChrisRD]

Doesn't sound like anything to be too concerned about...

That said, I'm not sure I follow your logic. Even though your skimmer may be working at maximum capacity and pulling lots of stuff out, that doesn't mean a better skimmer wouldn't pull more stuff out and result in less crap collecting at the surface of your sump. :wink:

Breaking up the crud with more water flow or a powerhead might help more of it get removed... ...or not. Maybe it just keeps it from accumulating in that one spot and it just stays mixed in the water column... ...I don't claim to know...

What I can tell you is that I have about 4X flow through the sump on my 180 FOWLR and had noticeable surface slime in the last chamber of the sump until I upgraded the skimmer - now nothing. Both pull lots of skimmate but the new one pulls more. I've seen this trend on past setups too.

Bottom line - if your tank looks good and you're not having nutrient problems, I wouldn't be worried about a little sump scum...