Am I missing something? (megaflow question)

[BHF]

Okay, we all know the megaflow overflow is rated at aprox 600 gph. Now, I'm assuming this is using the 1" hole as a drain, and the 3/4" hole for the return.

But what if I were to, say, use both holes as drains (with seperate lines to the sump), and use something along the lines of the customflo for the return? On the surface, I can't see any problems with this, and I would guess I would be looking at a flow rate of about 900-1000 gph (maybe more, perhaps the math majors here could chime in).

Am I asking for trouble? Is this more trouble that it is worth? I can't imagine that I'm breaking new ground here. Who has tried this?

[prodman]

I have done that and it works fine. You just ned to bring your return over the back. I think I had closer to 1500gph through both holes. I also adapted up to 1.5" pvc right below the bulheads. One problem is more bubbles in sump. On my new tank I have just enough flow. Its much more quiet too.

[BHF]

Hmmm....like the idea of plumbing it to one return. Should have thought of that. Now, you say you had more bubbles in your sump. Did that translate to more in your display tank as well?

[prodman]

Well I had a large sump with a good bubble trap where the water entered the sump. The bubbles were not so bad it was just alot of flow in a sump.

[Ereefic]

Are you planning on one taking the load and the other as a back up, just in case something clogs something?

[BHF]

I suppose that would be an added benefit. Really I was just brainstorming ways that I might increase the flow.

[Ereefic]

You don't need tons of flow through the sump really. If your running more through your sump than your skimmer can process, it's a waste IMO. All of your flow in the display should not come from the return, but from powerheads, closed loop, etc.

[BHF]

I see where you are coming from. But let me ask you this, if your return is split into, say, two (or more) spouts and a spray bar, wouldn't that alleveate (sp) the need for powerheads (at least to a degree)?

Or, put another way:

Return with three spouts and a spraybar putting out roughly 1400-1500 gph in a 90 gallon would equal what in terms of powerheads?

[Ereefic]

The main problems with flowing that much water though a sump (generally not a real big sump), is noise and microbubbles.

What your saying will work, but I don't think it's the best way to go about getting flow in the tank.

If your return is your only source of flow, what happens if that pump fails? You now have no flow in your tank.

If you have powerheads or a closed loop and your return pump fails, not so big a deal.

Using the flow properly is more important than having tons of flow, IMO.

[BHF]

<a href=showthread.php?s=&postid=7917083#post7917083 target=_blank>Originally posted</a> by Ereefic

If your return is your only source of flow, what happens if that pump fails? You now have no flow in your tank.

If you have powerheads or a closed loop and your return pump fails, not so big a deal.


Excellent point, and one worth chewing on to be sure. As I had planned on only having mushrooms, zoos, and one (maybe two) nems, perhaps a high flow isn't that much of an issue. Two strategicly placed PHs would probably suit my purposes. Dunno. More to think about, more to think about....

[allykahn]

I was in the same boat...thinking of using all four holes as drains. Decided against it because it would have been too much flow through the sump.

I used the 3/4" returns as emergency drains to the sump and I ran 2 return lines at the back of the tank to (2) 3/4" sea swirls.