Clossed loop return questions/idea help

[Crusty Old Shellback]

Ok I need a little help here in figuring out where I want to place my returns for a closed loop. Here's the basics:
7'L X 2.5'W X 3'T, 400G acrylic tank viewable from front and one end w/ center overflow
Sump return is a Sequence dart w/ 2 X 1 1/2" line over the top of the back about 12" either side of center overflow pointing towards the lower front corner
Closed loop #1 is a sequence hammerhead w/ 4 X 1" intake ports, two on each angled side of the overflow and return is 2 X 1 1/2" bulkheads in the bottom, about 1 1/2' in from the ends. This will be covered w/ LR to disperse the water flow. This C/L also has a large swimming pool canister filter in it's loop
Closed loop #2 is a Sequence Barracuda w/ 2 X 1 1/2" intake ports 10" up from the bottom and 3" out from the sides of the center overflow. The return will be plumed thru a OM 4 way with one port at a time open.

Now here's the question, where to place my returns for the best effect/flow. I want to place 2 on each end of the tank. The viewing end will require for them to be either at the top or bottom of that end so that I can cover the plumbing with a wooden fixture to dress it out. If I place them near the bottom, I was thinking of attching a 45 degree elbow to direct the water up off the sand so as to not disturb it. If I place them near the top, then I can leave just the bulkhead so as not to have anything intrude into the tank and just let it flow across the top. Or I can add a 45 there as well to direct the water down towards the center of the tank.
As for the other end, I can place them anywhere as that is not a viewing panel. Possibly place them towards the middle, or have them mimic the other end.

Any ideas on which will be the best way to get a good "wave" action going from end to end. The tank will have LPS towards the bottom and Monti Cap SPS towards the top. This will be a mainly Monti Cap dominated tank with a few other plating types of SPS corals.

 

[2fishy]

Holy Cow that is a big tank! I don't have a clue what the answer is but I wanted to give you a bump to the front!

 

[stereomandan]

Do you want the ability for targeting flow at all? The only potential issues I see with your setup:

1) Are your pump exit tubing so large in diameter that the water velocity is too low to reach very far in such a large tank? 1 1/2" is a large tube and it wil take a LOT of flow to make it reach far into the tank. Maybe with the huge pumps you are using it will be o.k.

2) Having fixed locations for the pump exit flow prohibits the ability to create a more random flow pattern. In my 90g, I'm going to use eight 3/4" Lock-line exits from a Sequence Snapper (2500GPH) and I'm worried that my velocity will be low, but having so many flow nozzles will be great for setting up a random/chaotic flow and targeting areas that might end up with little flow.

Just some thoughts.

Dan

 

[john rochon]

I'm looking into the MANIFOLD idea.
also, thats just a TON!!! of flow. maybe to much IMO.
I have a 500g and used a HAMMER HEAD for closed loop. tons of flow.

 

[SDguy]

<a href=showthread.php?s=&postid=8232081#post8232081 target=_blank>Originally posted</a> by john rochon
I'm looking into the MANIFOLD idea.
also, thats just a TON!!! of flow. maybe to much IMO.
I have a 500g and used a HAMMER HEAD for closed loop. tons of flow.

Interesting, I use a hammerhead on my 115g. Also tons of flow, but not too much IMO.

 

[MCary]

This is what I did:

Mine is a bare bottom, but this was the reasoning. The two back outlets push waste toward the front. The Oceans motions then turns on the front outlets. The side one on the front shoots the waste coming from the back along the front edge where the upward outlet shoots it up and over the overflow. This very efficiently clears the waste but it also created a nice dynamic flow. I also have a small closed loop in the very deep overflow box and a tunze to stir the top.

Mike

 

[bradleyj]

Here is how I added my closed loop to my 225g. Using a dart for my return and another dart for my closed loop.

 

[Crusty Old Shellback]

Thanks for the input so far. Keep them coming.

As for the too much flow question, I don't think so. I had 2 hammerheads running on it in the past and that still didn't seem like enough flow. Granted that with the head pressure and pipe restrictions, the output was cut down some.

I'm trying to keep away from having "equipment" inside the tank so that's why I have the bulkheads and external pumps. I also don't want to be putting in locline as it will be seen.

stereomandan; the miimum output piping size for the pump is 1 1/2". The Om 4 way has a 2" input and 1 1/2" output size. Since there will be only one output at a time that will have flow, I don't think the 1 1/2" pipe will matter. I'm not looking for targeting flow but more trying to get some wave action going back and forth across the tank so that I can watch my LPS corals "sway" in the currents.

 

[stereomandan]

Sounds good.

Yeah, my Snapper has a 1 1/2" outlet too, and I'm trying to find the best way to take that down to the eight 3/4" lock line outlets I have planned. I may have to resort to the standard reducers.

Dan

 

[reef_ky]

i used a sequence hammerhead with 2- 1.5in strainers to provide water to the pump (placed in the back center of the tank) & the pump returns to a 1.5in manifold with 16- 3/4in locklines. my tank is a 315gal. (7'L, 2'W, 3'tall) provides tons of flow, and I can direct it where i want it......