Water Flow and Sumps

[Jimbo]

I'm currently setting up my new 90g tank with a 50g sump, and I'm in 2 minds about the amount of flow required through my tank and sump.

I've read in the various books, magazines, and forums, that flow should be anywhere between 10 and 30 times the total water volume per hour depending on the types of coral (soft or hard). I'm planning on keeping a mixture, so I'm thinking of running 10 times the volume through my tank - approximately 1100g per hour, after taking into consideration the additional water in the sump and allowing for water displacement from live rock.

My questions are, should I:
a) Run the entire 1100g of water through the sump, and pump it back into the display tank
or
b) Run the pump at a lower rate (for example 600g per hour) and use power heads to supplement the flow.

I've heard some reefers say that you shouldn't run a high flow through the sump if you will also be using it as a refugium, but then other have advocated that a high sump flow isn't an issue, especially if you want to use part of the sump as a frag tank.

I'm still in the process of configuring my sump plumbing, so if I opt to pass the entire 1100g of water through the sump I can split the flow from the display tank between the first stage of the sump, where the skimmer will be placed, and the final stage that leads to the return pump.

Personally, I find power heads detract from the beauty of the life inside the tank and become an extra headache to look after.

Does anyone have any opinions on this?

[Greatwhite]

Most "experts" will tell you that low flow through your sump/fuge is better, especially if you have chaeto in there...

The return pump will never have enough flow to cause effective water movement in the display tank.  Your live rock and sandbed are biological filters and you want a nice flow over the live rock surface to let it do its job. 

Dead zones in the tank will also turn bad with  algae, nitrates and other bad stuff.

Power heads are not pretty... But they are the most effective way to move water around in your tank without doing some real nice custom plumbing with a closed loop and return lines hidden in the rock work.

[xbrentx]

How do people get flow in the corners?  I find they are dead spots

[Darth]

there are always going to be some sort of dead spots, but if you angle the powerheads, and think about how the water is hitting the rocks, then you get an idea of where it is going, a good way to test the flow, is after you set up, before you put in ANY livestock drop in some frozen corn (it floats so you don't have to worry about losing it) and see where it flows, then you can adjust according. With the tank set up its gonna be trial and error

[Greatwhite]

My corners are not quite "dead", but I'm sure they are close to it... I have my powerheads in the corners of my tank so that the suction draws water up the corner and blows out over the rock.  It's a very low flow area, but it's better than nothing.

[Greatwhite]

Oh, and I see where my water flow is when I feed my fish... anywhere thawed brine shrimp goes - there's some flow.   Any brine shrimp that get sucked into the powerheads just get shot out.  (And I don't have to pick corn out of my rock)

[Jimbo]

Most "experts" will tell you that low flow through your sump/fuge is better, especially if you have chaeto in there...

Hi GW,

I've seen quite a few sump/refugiums where the tank owner split a high volume overflow between the refugium and the skimmer before returning the water to the display tank. I'm guessing this would slow the flow through the refugium, while keeping high flow rates in through the display tank.

The return pump will never have enough flow to cause effective water movement in the display tank.  Your live rock and sandbed are biological filters and you want a nice flow over the live rock surface to let it do its job. 

Can you explain your reasoning here? Wouldn't it stand to reason that if you are pump 10 times the water volume per hour through your tank, and if you use a series of lines from the return pump to your display tank you should get good flow assuming appropriate placement of the return lines?

Any thoughts on this are appreciated.

[Hookup]

Most "experts" will tell you that low flow through your sump/fuge is better, especially if you have chaeto in there...

I 100% subscribe to this advise... my 180g display has about 400gph turn over... (2.2x turn over)

My flow in my tank is about 8000gph due to closed loops (44x turn over)


HTH

[Greatwhite]

Can you explain your reasoning here? Wouldn't it stand to reason that if you are pump 10 times the water volume per hour through your tank, and if you use a series of lines from the return pump to your display tank you should get good flow assuming appropriate placement of the return lines?

Well, my main reasoning is that my return line has 2 outputs.. If you want to plumb additional return lines and hang them over the sides into the tank at "key locations" you will certainly get the same effect as a bunch of powerheads.  But the question then is - what's uglier?  4 little round powerheads encrusted in coraline, or an octopus of return pipes?

If you were to do the octopus looking return, you need to keep at least 1 line up near the surface with a syphon stopping hole or you'll flood with a power outage.

I have heard of/seen sumps with high flow, and a fuge compartment on one side with not much more than a powerhead for water movement.  You are losing out of the benefits that you'd get by slowly passing water through chaeto for nutrient export and removal of bad stuff (like phospates)...

I've spoken with lots of experts on this subject, and watched & participated in debates - and I've always been won over to the low flow side.  Yes, both sides have their pros and cons.

[Jimbo]

Well, my main reasoning is that my return line has 2 outputs.. If you want to plumb additional return lines and hang them over the sides into the tank at "key locations" you will certainly get the same effect as a bunch of powerheads.  But the question then is - what's uglier?  4 little round powerheads encrusted in coraline, or an octopus of return pipes?

If you were to do the octopus looking return, you need to keep at least 1 line up near the surface with a syphon stopping hole or you'll flood with a power outage.

I have heard of/seen sumps with high flow, and a fuge compartment on one side with not much more than a powerhead for water movement.  You are losing out of the benefits that you'd get by slowly passing water through chaeto for nutrient export and removal of bad stuff (like phospates)...

I've spoken with lots of experts on this subject, and watched & participated in debates - and I've always been won over to the low flow side.  Yes, both sides have their pros and cons.

Thanks for the explanation. I definately get where you're coming from, although I'd still like to hide/remove the need for power heads.

After reading Hookup's comments, I was tempted to do a closed loop, with a second lower volume pump running through the sump/fuge, but the wife has put a stop to that.

I forgot to mention, that my new tank is being built into the wall seperating my fish room from the family room. So the family room will have a view of the display tank, and the fish room will get to see all the plumbing, sump/fuge, reactors, etc.

After explaining this to the wife, she's recommending the octopus thing as it will look cleaner from the display side, and we already have PVC check valves, ball valves, rigid and braided piping from plumbing we were supposed to use on a build a while back.

I'll post the progress in the build section, so I can get feedback as we progress. I'll also keep the forum posted on her successes or my failures of the different solutions we implement.

[Greatwhite]

Ohhhh - if you are building from scratch, look at Hookup's build thread...  He did some fun plumbing that has his returns all hidden in the rockwork.

Somehow I assumed that you had a system up and running and were looking for an alternative to powerheads.

http://ovas.ca/forum/index.php?topic=38958.300

The fun begins in the photos in post number 306 and 342...  I love the clean, final look of his tank.

If that's the look you're going for, he's the guy to talk to!

[Hookup]

thanks for the shout-out GW.

Always happy to help or let ppl know my experiences.

[Jimbo]

Okay guys, now i'm considering using powerheads after following up on your comments.

I've been looking at the Vortech MP10w and MP40w as possible options due to their low profile inside the tank, and low power consumption compared to a closed loop system.

Does anyone have a recommendation which I should go with for a 90g tank, and how many I should get?

[Greatwhite]

Okay guys, now i'm considering using powerheads after following up on your comments.

I've been looking at the Vortech MP10w and MP40w as possible options due to their low profile inside the tank, and low power consumption compared to a closed loop system.

Does anyone have a recommendation which I should go with for a 90g tank, and how many I should get?

Those things can move a LOT of water...  I think that a 90 would be good with one on either end.  You're right about the low profile, low energy consumption...  But you can't beat the whole "no electrical wires in your tank" feature.

Closed loop pumps can be energy hogs alright!

(but still look at that build thread.. holy heck!!!) 

[Hookup]

Okay guys, now i'm considering using powerheads after following up on your comments.

I've been looking at the Vortech MP10w and MP40w as possible options due to their low profile inside the tank, and low power consumption compared to a closed loop system.

Does anyone have a recommendation which I should go with for a 90g tank, and how many I should get?

MP40 x2

That way you can run them at 50% and you won't hear them at all... And when you want to blast the tank, you can jack em up to 100%...  And you want to do this..  I have slower head on a stick I use to blast my corals and rock work every month..  Helps dislodge any dteritus. That might be stuck

[fish]

Okay guys, now i'm considering using powerheads after following up on your comments.

I've been looking at the Vortech MP10w and MP40w as possible options due to their low profile inside the tank, and low power consumption compared to a closed loop system.

Does anyone have a recommendation which I should go with for a 90g tank, and how many I should get?

Are you sure an MP10 magnet will work with the glass thickness in a 90?

[NjOyRiD]

Are you sure an MP10 magnet will work with the glass thickness in a 90?

yes

[NjOyRiD]

Jimbo, you should come to the ovas meetings, we can talk about your set up and Ill answer all your questions

[Jimbo]

Jimbo, you should come to the ovas meetings, we can talk about your set up and Ill answer all your questions

Thanks, will do.