Figuring flow

[FishWife]

Hi.

 

Well, as you saw in the loop on leaking bulkheads, we're right about here now:

 

 

 

Tonight, we'd love to go buy a sequence dart pump for a 4' wide, HOB closed loop with three outflows to souse the tops of the rocks above (top half of the tank) with good strong turbulent flow.

 

We're thinking of three to four inflow spouts: one in each back corner (so, four feet apart) and one (maybe two using a three-way L pvc fitting) in the middle, pointed across the stream of the right spout (as you face the tank).

 

Here's a crude diagram, lookint from the top: The line is the back of the tank. The first 3 X's are flow into the tank. (Ignore the small dotted line; it isn't there, really... it's just holding the silly "X"'s in place 'cause the software's fighting the program ). The "O" is the flow out to the closed loop pump over the back of the tank.

 

__________________________________________

X.......... \___O________/ X X..............................X

 

 

Questions for the committee are two:

 

1. What size pipe? 1"? 1/2" (We used 1" and pinched back to 1/2 45-degree elbows at their ends in our manifold under the sand that you can see sticking up.) (This time, we plan to prime and paint. )

 

2. How strong a flow? Like, in gph. We need a pump to deliver thru 3-4 outlets... directly towards the upper 1/2 of the rocks above. What's a good gph for water to go whizzin' past corals? (Oh, we plan LPS and a few SPS's.)

 

TIA!

Edited October 15, 2007 by FishWife

[Rascal]

The Dart uses 2" intake and 1.5" outlet. Unrestricted it is rated for 3600 gph. If you use locline you can put "Y" fittings on each of your "x"s to turn those 3 returns into essentially six if the velocity is too much.

 

There are 2 measurements you are interested in in determining flow for your tank. One is the total gph being turned over in the tank. The other is the velocity of the water impacting the corals. You can get a lot of flow without too much velocity by increasing the diameter and number of your outlets.

 

I just switched to a Dart and couldn't be happier with it. If it is too much flow you can always dial it down a bit with a valve without doing any harm to the pump.

 

BRK runs a couple of them on their systems if you want to see/hear for yourself.