How important is return flow to the tank?

[heuerfan]

I have a 125 gallon tank with LPS, Zoos, Sofites. I am running a Eheim 1250 from my sump back to the tank. I also have two maxijet 1200 in the tank for additional flow. I don't plan on going SPS at the moment.

My friend has an extra Eheim 1260 that i could use but i don't know if its is necessary for me to add the extra flow. I know more flow means faster turn over of the tank water to sump, skimmer but its going to get there regardless i figure.

Thanks for your thoughts,
Steven

Eheim 1250 rated for 320 GPH at 28 watts
Eheim 1260 rated for 634 GPH at 65 watts

 

[DeepBlueSea]

That seems like a very weak pump for a 125... I'm interested to see what others have to say


I've often thought about "how important" turn over is... I used to run a 75 gal with approx 1500gph of turn over... however, i really don't understand if this is needed, if you have some sort of closed loop or powerheads within the main display...

 

[amike5]

There is no need to increase your flow through your sump. You could however use it on a closed loop for additional flow within your tank.

 

[Village Idiot]

I have a 1262 on my 90. It's throttled back a bit so I don't overwhelm my overflow, but I still get bubble/scum in my wad of chaeto in the sump/fuge, so I don't think I have too much flow. The chaeto grows like the weed it is.

A 1250 seems a bit small for such a large tank...but as they say: "If it ain't broke, don't fix it."

 

[gig]

I got a dart running my 180g system (247g total), it pumps 3600 gph.

 

[Craig Lambert]

3-5 times turnover through the sump is all you need. You will skim more efficiently and the system will be quieter. I would add some flow via powerheads though because your total tank turnover is very low. Without sps in the tank it can be lower, but I would still shoot for 20X as a minimum.

 

[heuerfan]

Thanks everyone for your feedback. Maybe i'll will try and see how it goes with the 1260 since i have it already. Just don't want to see all the corals being blown away by the added flow.

 

[Goodwood]

your fine on sump turnover, water flow in the main tank is key. 3x turnover i the sump is all you need, anything more is just wasted money.

 

[amike5]

<a href=showthread.php?s=&postid=9939201#post9939201 target=_blank>Originally posted</a> by heuerfan
Thanks everyone for your feedback. Maybe i'll will try and see how it goes with the 1260 since i have it already. Just don't want to see all the corals being blown away by the added flow.

Don't worry about the corals, the ocean provides hundreds of times more flow than we could ever possibly put into our tanks.

 

[Phoric]

I have 3 powerheads (MJ 900, 600, and 400) in a 29gal, not including the MJ powering the skimmer. It's just barely enough.

 

[heuerfan]

Thanks, not all corals like lots of flow from my experience. For example, my frogspawn, hammer, torch corals don't like being blown around and will not open up entirely under lots of flow. As well as my gonioporas.

 

[flyyyguy]

Assuming you arent T'ing off of your retunr pump to run any cansiter filters or chillers, your return pump should be roughly matched to the amount of water that your skimmer can process. There is no point in moving any more water through your sump than this. The goal is to send as little unskimmed water back to the tank as possible.

 

[MrSpiffy]

If the flow is too much, you can always add a ball valve to throttle it back a bit. You could even add a "T" fitting with two valves to let some of that back into the sump.

Interesting how I see that people are saying here that 3x-5x turnover is good to shoot for. But when I thought about adding a Mag 3 to my 30G for a return, I was told to go bigger, even though I was in that range. What's the reasoning for always being told to go with a bigger pump?

 

[areze]

well there is head loss to consider.

flow is good, but theres no reason to put that flow through the sump. that'll just promote noise and micro bubbles. flow should be kept in the display, with power heads or closed loops. the sump loop should not be regarded as a primary source of circulation for your tank.

bottom line, I dont know why people told you to go bigger, most likely simple misinformation unfortunatly.

 

[areze]

btw, throttling back is a possiblity, or Ting off back into the sump, in both cases your just inviting extra heat, and more electricity, not to mention noise that you dont really need. so in a case like this, where your pump is fine, I wouldnt step it up just because the offer for free is there.

 

[Crusty Old Shellback]

<a href=showthread.php?s=&postid=9939744#post9939744 target=_blank>Originally posted</a> by flyyyguy
your return pump should be roughly matched to the amount of water that your skimmer can process. There is no point in moving any more water through your sump than this. The goal is to send as little unskimmed water back to the tank as possible.

BINGO! We have a winner. You only need as much flow thru the sump as your skimmer can handel. It's Ok to go a bit more but less is pretty much a waste of time.

My current 400G tank uses a Dart for my return pump. But that is because I use 3 Sedra 9000's to feed my skimmer. Even at 3600 GPH - Head pressure, the majority of that flow is thru my skimmer with very little not going thur it.

You alway want to feed your skimmer with fresh dirty tank water. If your return pump is underrated, then you wind up recycling the skimmer water in the tank vice adding in fresh water all the time.

 

[heuerfan]

Interesting, my skimmer is rated for 250 gallons, so my eheim 1250 should suffice. I calculated the head loss and i'm getting about 250 gph.

Thanks for everyones comments.

 

[flyyyguy]

<a href=showthread.php?s=&postid=9939905#post9939905 target=_blank>Originally posted</a> by heuerfan
Interesting, my skimmer is rated for 250 gallons, so my eheim 1250 should suffice. I calculated the head loss and i'm getting about 250 gph.

Thanks for everyones comments.

it doesnt necessarily matter what your skimmer is rated for. It matters what skimmer and pump you are using and how much water it actually processes. For instance, a skimmer using a 500 gph needlewheel pump, will be processing (this is a guess for conversation purposes)......350 gph. Remember, its pumping air with that water.

Your pump very well could be perfect.......but just clarifying the "matching" return flow to skimming concept.

 

[corals b 4 bills]

You only have two MJ 1200's? Are they mods? you might want to kick up your flow on a 125, I have a 155 with a mag 18 for a return by the time it hit's tank water it's putting out about 650 gph, so with my tunze's combined I have 10,000 gph on a LPS/softy tank. after a couple of weeks with this much flow the corals begin to dig it.

 

[flyyyguy]

Reefkeeper - (ref-ke-per) n: Individual obsessed with placing disturbing amounts of electricity and seawater in close proximity



lol