closed loop question

[sarmo]

i am currently using two mag 18's on one end of my tank for flow. they are doing a great job BUT they are noisy and their flow direction is not adjustable.

i'd like to replace them with a closed loop. and i'd like to maintain or increase the volume and pressure of flow. i have been looking online and dolphin and sequence have pumps that produce enough flow ( i think). i plan on putting the pump in my crawl space so it will be about 10 feet below my tank. my tank is not drilled so i was planning on usind a 1 1/2" pipe for an overflow. and then i would return the back into the tank with 2 or 3 3/4" lock line fittings.

my question is, does the 10 feet matter because of the siphion that will be created and the pressure from the height of the overflow. i will probably only have one or two elbows on the main return line before the lock line. i'm just trying to decide which pump i should use.

any help would be great. thanks

 

[Krish]

I've always heard great things about Sequence pumps! They also make pressure rated pumps that will pump that 10ft of head without losing 1 gph of flow. If I ever went with a big closed loop setup, that would be the pump I'd use

 

[Willy]

You wont have to worry about a siphon on a closed loop. I 2nd the sequence pumps, for your application Id look into the barracuda or the hammerhead. As for your plumbing use 1½" - 2" pipe to feed the pump. On the output use 1½" pipe and then reduce it down to 3/4" as close to the end as possible. You could tee off the return line several times to give you multiple outputs. I think you will be very happy with the sequence pumps. I have a reeflo dart powered closed loop on my 75 and it creates plenty of flow for me, and I have it flowing through 5 outputs.

 

[sarmo]

hey, thanks . anybody else have any ideas or suggestions? if i go with 2" drain line, do they make a strainer to keep fish out for that size pipe?

 

[Frankie]

I'm useing an ampmaster 3000 on my CL and it works great. Im not to sure about head preasure though. 10 ft is quite a drop and return. You need to reserch that kind of head preasure before buying. Mike (mojo) helped me pick out the right pump for my setup so i'll recomend pming him about this. Good luck!

 

[Scooterman]

You don't need to worry about 10' of head because in a CL what you loose you also gain because you have to run suction & returns the same length, your head loss will be very little because of that & the fact it is closed. I would plan on going with at least 4 outlets & using "Y" adapters splitting the flow into 8 outlets with the locline. When you go over the top like this you need to allow for priming of the pump, you will need to have a threaded Tee up top somewhere, & when you go back into the tank for the suction just multi drill the PVC all the way down to lessen the suction, I would use 2" for that part also to lesson the suction.

 

[CarlaW]

You don't need to worry about 10' of head because in a CL what you loose you also gain because you have to run suction & returns the same length, your head loss will be very little because of that & the fact it is closed. I would plan on going with at least 4 outlets & using "Y" adapters splitting the flow into 8 outlets with the locline. When you go over the top like this you need to allow for priming of the pump, you will need to have a threaded Tee up top somewhere, & when you go back into the tank for the suction just multi drill the PVC all the way down to lessen the suction, I would use 2" for that part also to lesson the suction.

I was wondering when someone would catch on!!!! Good call Scooter.

 

[ronj]

if i go with 2" drain line, do they make a strainer to keep fish out for that size pipe?

here you go...i got a large stariner from here as well
http://www.premiumaquatics.com/Merc...Product_Code=BH20-STR&Category_Code=Bulkheads

 

[CarlaW]

Wasn't there a recent thread on a intake strainer mod here lately??? It looked pretty nifty!!! I think bigt was the one who came up with it, but I can't seem to find it????

Found it,
http://www.reeffrontiers.com/forums/showthread.php?t=11349

 

[Scooterman]

First of all if your not drilling the tank you don't have a BH for the suction, it is just pipe, you don't need the strainer!

 

[Krish]

You could still use strainers with PVC like I did if you want, or put a cap on the bottom and drill tons of holes for the suction

 

[ronj]

i actually made my first one with a miter saw...i have part of it on my closed loop right now......if you cap the end off, you can just use the small cuts in the pipe as the intake..i just went ahead and added a strainer anyway..here is a pic

 

[CarlaW]

i actually made my first one with a miter saw...i have part of it on my closed loop right now......if you cap the end off, you can just use the small cuts in the pipe as the intake..i just went ahead and added a strainer anyway..here is a pic

That is a good idea also, just to be safe, I would use the strainer. We have heard enuf horror stories about stuff gettin sucked into anything. Better sfae than sorry IMO.

 

[ronj]

First of all if your not drilling the tank you don't have a BH for the suction, it is just pipe, you don't need the strainer!

the strainer is to keep fish out...i cut the slits in my pipe and i was still worried about a fish getting stuck to the pipe, so i got the strainer....the more places for water to go in the pipe, the harder it will be for the fish to get stuck..i wanted the suction to be spread out and not just in one area

 

[Krish]

Here's a pic of what I had mentioned earlier about putting a cap on the plumbing and drilling tons of holes for the suction


http://www.melevsreef.com/closedloop.html

 

[ronj]

that's the first way i did my old one..i ended up changing it to the straight cuts in the pvc

 

[Scooterman]

slots work also, that is why I mentioned larger pipe & yea you need a ton of holes to disperse the suction.

 

[sarmo]

how much flow can a pressure rated pump like sequence push through a 3/4" lock line nozzel or 3" fan? right now the mag 18's are pushing 1800gph through a 3/4" opening so i want to match that at least.
since there shouldn't be much loss of flow due to the closed loop then the only loss i should expect is from elbows and pipe diameter reduction? i'm just trying to figure out which pump i should buy? any suggestions?

thanks for alll the help so far

 

[sarmo]

currently i'm using a total of 3 mag 18's

 

[CarlaW]

how much flow can a pressure rated pump like sequence push through a 3/4" lock line nozzel or 3" fan? right now the mag 18's are pushing 1800gph through a 3/4" opening so i want to match that at least.
since there shouldn't be much loss of flow due to the closed loop then the only loss i should expect is from elbows and pipe diameter reduction? i'm just trying to figure out which pump i should buy? any suggestions?

thanks for alll the help so far

I'll call you today Rob.
I am thinking a big Ampmaster or a Sequence pump. I'll bring the Marine Depot catalog up.