Flow Rate question

[BobDaMann]

Hello everybody. First post here.

I just recently got into the hobby with a 47 Gallon Column tank which was a gift to me, but after realizing it would be difficult to light properly I switched to a 56 gallon tank, but then realized I would want something a little bigger. So I ended up buying a 75 Gallon tank, already drilled for a sump, used in town.

So now I have everything moved from my 56 gallon tank to the new 75 gallon tank with a sump. I had two SEIO(530GPH) powerheads in my old tank, but now I was wondering how much flow do I really need in this new tank, since it has an overflow and a sump. I'd prefer to remove the powerheads from the 75 gallon tank, because they are an eye-sore. My friends ask me why I have web-cams in the tank, I always crack up at that one.


I am using a Mag5 as a return pump from the sump, which I believe is running around the 300GPH range after head-loss. Also I have a durso stand-pipe in the overflow chamber, if that effects anything in terms of flow rate.

I know the photo is large, but I wanted to have a clear view of my powerhead placement, because if I do need to keep them I would like to have input on better placement etc.

So how much water do I need to push around?

If I need to keep the powerhead's were should I place them?

I appreciate any help or advice. Thanks in advance

 

[James79]

Sumbersible web-reef cam thats disguised as a PH. You could spy on the babysitter from a fish POV.
I think 10X the total volume in flow is recommended for medium flow, some have a lot more.

 

[jon99]

Kind of depends what you're doing with it. SOme coral like lots of flow others not so much. Your tangs like highly oxygenated flowing water. They are often found in the intertidal zone where water movment is pretty significant. Your best bet would be to install a closed loop. That way you can get rid of the powerheads while still maintaining/increasing flow. This ofcourse requires you drilling your tank which from the looks of it isn't somthing you probably want to do. Soooo the next best bet is one of these...
http://www.melevsreef.com/closedloop.html
Not too difficult to put together if you're handy. If not email Marc, maybe he'll build you one

 

[BobDaMann]

Ya, I have been looking at quite a few topics on Melevsreef, mainly the sump design and ATO.

Would it be possible to upgrade from a Mag5 to a more powerful return pump that would allow for greater flow AND add some plumbing to allow for multiple outlets for the water? Then remove the power heads all together?

I am new to this, I am trying to learn as quick as possible. However, it gets overwhelming quick.

 

[jon99]

Before upgrading the retun pump make sure your overflow can handle the extra flow, otherwise... flood. If you know how many overflows and size you can do some calculations here... http://www.reefcentral.org/calc/drain.php

BUT you usually don't want turn over in your sump being more than 3-5 times the size of your display tank. In other words on you 75 gallon you don't want a return pump pushing more than 375gph. I mean it can be done but can potentailly lead to microbubbles problems in the display tank, plus limits the waters "dwell time" in the sump where it is skimmed, heated, filtered, etc. Here is some more on this... http://reefcentral.com/forums/showthread.php?s=&threadid=1338719

 

[Mariner]

Yep, you don't want much more flow going through your sump, even if your plumbing could handle it.
IMO, 10x tank volume (750gph in your case) would be the very minimum amount of flow you'd want, and probably not adequate since you're keeping tangs. I shoot for 25x in my tanks, and many others go with much more. The more flow you have, the more waste particles will stay in suspension, enabling your skimmer and filters to work more effeciently. Most corals also enjoy generous amounts of flow to bring nutrients to them and wash waste away.
I know you said you don't like powerheads, but a single modded MaxiJet1200 would give you an additional 1600gph.
FWIW,
Mariner

 

[BobDaMann]

Thanks. I appreciate all the help