internal overflow with closed loop - opinions please

[cinnamongirl]

Hello
Here are my plans for an internal overflow with a closed loop in a 46g bowfront designed for seahorses.

First, the overflow. I plan on putting the pump in the back corner of the tank, plumbed straight up into a T into a closed loop manifold around the top of the tank. There's no overflow built into the tank, so instead of just having the pump sit there sucking up my poor little seahorses, I was going to enclose it by siliconing two pieces of plex to the back corner to make my own internal overflow. I will cut teeth out of the top.

Second, the manifold. It's made from 3/4" cpvc on the back and sides, and the front is 3/4" ID flexible PVC. There are two tee's in the back, one in each side, and one in the front center that splits into a tee pointing left/right. The tee's are 1/2" into 1/2" loc-line with a 1.25" flair nozzle. I also ordered 1/2" ballvalves from loc-line so I can control the flow from each T.

Last, the pump. I'm not sure what I need to use, as this is my first attempt at a closed loop. I have a Mag7 that I didn't think would be large enough. I also have a Mag12, which I think may be too much. Does anyone know how to calculate the flow with this setup? How much flow do I need for seahorses? I know it's a lot less than a typical reef.

Thanks for your help!

[cinnamongirl]

Here is my attempt at a drawing....

[Anthony Calfo]

overall it looks fab, although I would definitely use the mag 12... and I'm not sure that will even give you the flow you want for 6 tees.

You may be OK though... the 1/2" outlets will increase velocity of flow there.

You will want to step the loop pipe diameter up to 1" though (less friction, more flow)

Else it looks pretty good for a tank this size

Let us know how it evolves, please!

[cinnamongirl]

Yay, you're back!!

I fitted this contraption together, dropped the Mag12 in a 5g bucket in the yard to test it, and the bucket drained 4g of water in 16 seconds. That translates to an aweful lot of flow!!! By my calculations, thats 900gph! Could that be realistic, or isn't my little test a valid one?

[Anthony Calfo]

consider it another way, love...

1200 gallons per hour distributed to 6 outlets is 200 gph per.

200gph is less than a small powerhead... a mere trickle as effluents go.

[cinnamongirl]

So what you are saying is that it is 200 gph flow in the tank, but 1200 gallons per hour turnover?

This is acceptable for seahorses?

[Anthony Calfo]

no, my friend... 200 gph per outlet... six outlets in the tank for a total of 1200 gph. And this will all be (too badly) diffused to adequately keep solids in suspension. Very weak.

[cinnamongirl]

I apologize that I am having such a mental block with this (but I warned you a while ago that I was plumbing-illiterate!)

So with this pump I will have a turnover of 1200gph (appx) in my 46g tank. Isn't that like a 26x turnover an hour?

[Anthony Calfo]

yes... but it is very diffused because you have six tees... you will scarcely notice the flow. It will be very weak.

And folks have used too little flow for too long. The reef (including seahorse locations) is far more dynamic than our aquaria.

[Chihuahua6]

Victoria can I ask what program you used to make that diagram? It looks great.

[cinnamongirl]

Thanks! I made it in Photoshop, actually.

Anthony, I agree with the flow issue. I'm trying to get more flow in my 75g right now, but I'm having trouble with getting it to the right spaces without blowing my poor corals out of their skeleton. I'm having a bubble issue right now, as I think my sump is too small and the bubbles from the PS are not disappating in time befoer they get sucked back up to the display. Once I get this manifold thing under control, my next step is to build one on my reef tank and get a MUCH larger sump.

So many projects!!!