Question,Closed Loop with Sequence Dart pump

Robert Patterso · #1 12/05/2007, 07:21 PM

Here's what I'm doing. I'm setting up a new 140gal. tank. It will be acro/sps dominated. The tank has been drilled in 5 places for a closed loop. 4 holes for returns @ 1" and one for feed to the pump, here's the kicker the bulkhead that drains to the pump is also just a 1". I was thinking of using the Sequence Dart for the CLS but have been told the drain to the pump isn't big enough and will starve the pump. The drain to the pump is in the bottom of tank. The tank builder said it would be plenty big enough because it is in the bottom. True or Not? 2 of the returns are also in the bottom panel on opposite ends of tank at front of tank and 2 are in the back panel. It is my understanding that there is no headloss in a closed loop but on another forum was told that is not true and that I would have a substantial loss of gph with this set-up. True of False. If any of the above is true will redrilling the tank out for a larger drain to the pump take of the problem? The entire filtering system, sump, pumps ect. will be located in a closet directly behind tank in another room. All input will be appreciated. Would like to know where I'm going before I get there so I don't have to turn around and go back.

Thanks, Robert

oct2274 · #2 12/05/2007, 07:31 PM

you will not be able to use 1" return plumbing. Minimum of 2" on the inlet. On the outlet you need to use atleast 1.5 inch plumbing to where it splits to 4. These pumps are really bad under head pressure so the straighter you can make the plumbing to the 4 outlets the better. You will definitely starve the pump if you use less the 2" to the inlet. You can also use multiple intakes that combine together and run to a 2" inlet size.

Robert Patterso · #3 12/05/2007, 07:38 PM

I plan to run 2" plumbing directly from bulk head via adaptors from 1" to 2" which will then go directly to pump. I plan to have a few 90 deg. elbows ect. as possible. My main worry is that the 1" bulkhead wouldn't be enough even though it would immediately go to 2" plumbing. I couldn't see drilling the tank for a 2" bulk head, thats a pretty big hole.

oct2274 · #4 12/05/2007, 07:49 PM

a 1" bulkhead can only flow around 600 gph 900gph at the very most. the dart is capable of flowing 3600 gph with no headpressure. not going to work. You need to supply this pump with plumbing that will get enough water to it. If you don't want to drill, Plumb another intake over the top edge of the aquarium. Just make sure the intake is probably 6 inches under the water cause otherwise it may create a vortex and start sucking air from the surface. You will have to use some sort of screen on this intake to keep from sucking animals and other bad things in.

Robert Patterso · #5 12/05/2007, 09:11 PM

oct2274, I assume that's your birthday? If so good month and day. Mine also, oct2255. Anyways, obviously I want to get as much out of the pump as possible. Trying to avoid using to many powerheads. Don't want to pay 800.00+ for Tunze's although I know they a very good pump. So, I can either sacrifice one of the return holes which would then give me 2 1" supplies to the inlet OR plumb a 2" line that goes over the back of the tank to feed the pump. Will the pump pull the water over or how would I get the flow going. I would then have 5 1" returns going to the tank. A 2" bulkhead requires a hole of at least 2 7/8 up to 3 1/4. The bottom of tank is 3/4" glass. I'm open to ideas, got any? Would you maybe suggest a different pump or would I still be in the same boat.

mg426 · #6 12/05/2007, 10:11 PM

Here is a (not so good) picture of an old setup I used on a 125 with the over the tank method. It worked very well. I took the White cap off the top to prime the pump. Sequence dart.

Robert Patterso · #7 12/05/2007, 10:17 PM

Quote:

Originally posted by mg426
Here is a (not so good) picture of an old setup I used on a 125 with the over the tank method. It worked very well. I took the White cap off the top to prime the pump. Sequence dart.

mg426, did you just fill the down pipe going to the pump with tank water to get it going? Once it was running was there any problems keeping it running?

Thanks

viggen · #8 12/06/2007, 02:06 PM

I would think your only option (due to how the tank man. made the tank) is to run the 2 in inlet over the top of the tank. Using 2 1 in inlets still isn't enough to allow the Dart to run like it should.

You can also simply stick a tube in the plumbing & suck out the air. I used the airline tube to start mine up & it works great! It doesn't take much.... sucking... to get the pump's impeller submerged which allows you to turn the pump on.

oct2274 · #9 12/06/2007, 02:29 PM

the pump will need to be primed initially with water in the tube. Once it gets going you will never have to worry about it unless the water level in the tank gets low enough to where the pump sucks air into the intake tube. If you want to do two intakes instead of one large one you will need to use atleast 1 1/4 inch pvc for the two intakes and use a 2 inch Y adapter. You can adapt the 1 1/4 inch intakes to the 2 inch Y. A Y piece is preferrable to a T to join the two intakes if you can find one because they flow better.

Kung · #10 12/06/2007, 02:46 PM

Abandon the plan and send that Dart to me IMMEDIATELY.

Just kidding. Drill another intake.

I have two 1.5" intakes and plan to get a dart very soon to run my closed loop.

oct2274 · #11 12/06/2007, 03:07 PM

whatever you do, i would highly recommend putting a ball valve on both the intake and output side of the pump so you can remove it for maintenance. I would also use unions in strategic spots in the plumbing so that you can easily take it apart if needed.

mg426 · #12 12/06/2007, 04:59 PM

Quote:

Originally posted by oct2274
whatever you do, i would highly recommend putting a ball valve on both the intake and output side of the pump so you can remove it for maintenance. I would also use unions in strategic spots in the plumbing so that you can easily take it apart if needed.

I would highly agree with that statement, as you can see in the picture I did not do that the first time around. It is one ROYAL pain to work on without valaves and unions, trust me. I have since redone the entire plumbing to include valves and unions (I just have no pics at the moment) To prime the pump is a matter of pouring a couple gallons of water down the intake tube by removing the cap. Once the pump is running the air will be blown out and you are set. You can shut it off and restart it with no problem at all.