Is there a significant advantage to increased FLOWRATE ????

[meech]

I'm currently at a crossroads in my setup. I am one of the unfortunate few who happens to have a decent sized tank (120 gal) that is not reef ready (not drilled) !:smash: In my previous setup (which was a FOWLR) I was using my Amiricle wet/dry filter which came with an overflow box. The problem that I've always encountered was that my returm pump (MAG 9.5) was too powerful for the overflow box's capabilities. I've always had to slow down the flow on my return pump with a ball valve to compensate.
I'm aware that this has been discussed before, in fact the info that I found while doing the search has lead to my dilema.

I've seen a few recommendations for the Lifereef overflow boxes because apparently they offer a higher flowrate.

The question I have is this, does a really high flowrate offer any significant advantage over a slower one? If your tank water is RUSHING through your sump at 1400 gph, is it really getting the benefit of your skimmer/ fuge/ carbon/ heater/ liverock etc. ???? I understand that you want to have your tank water turned over often but at what stage does it become ineffective to have water flying through your sump at warpspeed. If there is a formula/ratio that I haven't seen then please point me in the right direction.


OPINIONS ??????????

 

[NYreefNoob]

water flow

from my understanding you really want a slower flow through sump\refugium. so that it can do what it is there for. you could always get a smaller return pump.

 

[Bob 1000]

I understand your dilema... I had the same one ,but a frien of mine just drilled the holes in my tank... I only had to take out 25% of the water...Changing my dilema to how do I stop that suction noise..But that was easy...

 

[Tonyscoots84]

as previously stated you want a slower run through your sump so your skimmer can perform and do what it has to do (if skimmer is in the sump and not being gravity fed)... it wont be nearly as efficient with 1400gph rushing around it and through ur sump... also with slower flow through your sump it gives time for the microbubbles to rise to the top and pop... ...

i would also recc. drilling the tank and getting rid of the overflow (dont get me wrong some people had success with em "devious" being one that comes to mind) but they are not the safest things to have... if flow is such an issue put a ball valve on ur return line and reduce the flow, so that the overflow matches the return or get a smaller pump that matches the overflow with the headpressure its going to have.....

good luck

 

[KathyC]

Great question Meech! Been wondering the same thing and would like to see more folks (yeah Tony!) chime in on why I keep reading that we should have a turnover rate of 10 or 20 or even 30 times the water volume per hour??

I run a Mag 12 on a 75g DT w/ a 30g sump/fuge..and I have an overflow box. I had to upgrade my OFB from a 600gph to a 1200gph (with 2 U-tubes) to balance out my flow better.
As far as the skimmer, I don't think the flow through the sump affects that, as the skimmer has it's own pump to control what is going in there.

It is my understanding that an OFB causes no more (or less) issues than a drilled tank (in a power outage) as long as you have siphon holes drilled in the proper place in your return piping.

 

[jhale]

like Tony said, a medium flow through the sump is better.
tank flow is created with power heads or closed loops.
if possible I would have the tank drilled, I never met an overflow box that did not cause a flood at some point.

 

[taat2d]

I'm almost afriad to ask this but here goes. What difference does it make if your OFB and return pump are equal in GPH flow? What are the benefits of this? I really want to get as much info on filters as possible cuz I'm about to upgrade mine.

 

[KathyC]

Very bascially the amount of water going into the tank from your pump (that is in your sump) needs to equal the amount of water that is flowing from your tank back to the sump...or at some point the pump (in the sump) will run out of water to send back to your tank.

The water flow in the tank itself is strictly the movement of water within your main tank, ans as JH pointed out, that is done with powerheads or a closed loop.


Did I get that right guys?

 

[taat2d]

Ok I got that. Now if you keep your overflow and return sump at the same flow rate with that quiet the gurgling sound as well?

 

[Tonyscoots84]

that gurgling sound is usually air rushing down with the water.... u have to eliminate that by letting the air escape somewhere, then the gurgling sound will disappear ....

here is 1 example that i stole from deanos :shhh:... the air when going down the overflow escapes from the opening in the 2nd pic..... water gets pushed down air gets pushed up.... noise gone ...

 

[meschaefer]

Great question Meech! Been wondering the same thing and would like to see more folks (yeah Tony!) chime in on why I keep reading that we should have a turnover rate of 10 or 20 or even 30 times the water volume per hour??

I run a Mag 12 on a 75g DT w/ a 30g sump/fuge..and I have an overflow box. I had to upgrade my OFB from a 600gph to a 1200gph (with 2 U-tubes) to balance out my flow better.
As far as the skimmer, I don't think the flow through the sump affects that, as the skimmer has it's own pump to control what is going in there.

It is my understanding that an OFB causes no more (or less) issues than a drilled tank (in a power outage) as long as you have siphon holes drilled in the proper place in your return piping.

It seems to me that when I first got started in this hobby (sometime in 2000) that there where not that many powerhead options, and good portion of the total flow in your tank came from your return. With newer and better powerheads, you don't need get all of your flow from your tank return.

Another reason to have a slower flow through your sump is that it helps get rid of microbubbles.

 

[taat2d]

that gurgling sound is usually air rushing down with the water.... u have to eliminate that by letting the air escape somewhere, then the gurgling sound will disappear ....

here is 1 example that i stole from deanos :shhh:... the air when going down the overflow escapes from the opening in the 2nd pic..... water gets pushed down air gets pushed up.... noise gone ...

Tony will this work on a HOB overflow? If there is a God the answer will be yes. LOL:help:

 

[Tonyscoots84]

well if you come out the bottom with a 90 degree elbow then connect that 2 a T and follow the deanos setup i think you should be fine... correct me if im wrong...