Sea Swirl on a closed-loop...

[Anonymous]

I set up a mag-drive 7 pump screwed to my canopy and plumbed to a 3/4 sea swirl. The first issue I noticed is that the pump is quite noisy, particularly when amplified by the canopy. I used a mousepad to soften the noise and was going to get rubber washers for the screws, but I have noticed that if it sits more than a couple of hours turned off the water drains out and the pump looses its prime. My plumbing all seems really tight; and doesn't leak water. I wonder if its possible that something inside the seaswirl isn't perfectly airtight?

I may have to put the pump on the ground, instead of above water level...

 

[GSchiemer]

The Mag drive pumps are intended to work with the suction side flooded. IOW, it was not intended to "lift" or "pull" water. It remains primed by being flooded with water. It will never work well in your present arrangement.

Greg

 

[Anonymous]

Hi Greg-

It is flooded- both inlets are below water and I removed the air by sucking it out with an airline tube. It runs fine, and even starts up after being off for an hour or two. Beyond that though, it looses the prime- just not sure where from...

I guess I am asking it to lift somewhat- but in this configuration I don't think it should be a problem.

 

[O P Ing]

hi.
Dan's setup with the mag is fine. The pump is not doing any lefting at all.

Dan, try to see where the bubble is coming from in the plastic tubing. If it goes from the SS to the pump, then the SS is leaking. If it goes from the pump to the SS, then the left side of the plumbing is leaking.

Double check for water leak, and make sure the SS and the pump is under water all the time.

 

[bowfront]

That's an interesting setup. I don't have an answer for your problem but just wanted to add that you can also run a Mag 7 submerged hidden behind the back of your reef. I switched out the barbed inlet fitting on the
SS for a thread/slip PVC 90 and turned it to the side instead of pointing backward. I used black flex tubing to run from the Mag to the SS so it's hardly noticable in the corner of the tank. Works great and is not any noiser than your basic submerged Mag.

 

[SPC]

Posted by Seven:

hi.
Dan's setup with the mag is fine. The pump is not doing any lefting at all.

-Seven, you are going to need to explain this to me. It sure looks like this pump is having to "lift" the water to me.? :?
Steve

 

[Chucker]

Dan, I bet it wouldn't hurt to cover your bases by adding a bit of non-toxic grease to those barbed fittings. That'd at least help eliminate the flex tube connection as a leak point.

 

[Anonymous]

Steve- I can't explain it in appropriate engineer's terminology; but basically I believe the down side of the loop cancels out the up side and thus the pump is just providing circulation.

 

[golfish]

I have to agree with Steve and Greg. That pump is really made to be stuffed with water, not pull\draw water. Its not being stuffed the way it is now.

If you lowered the pump so the impeller is underwater it will help quiet down the pump and speed up the flow. Most likely its cavitating a bit.

Mark

 

[O P Ing]

hi.
SPC, take a look at a siphon... and imagine it with a impeller in the middle. Now, does a siphon push water?

 

[Marrowbone]

I would suspect that the mag drive is the piece with the air leak over the Sea Swirl, or even your plumbing. I have a similar closed loop setup, except that it is a Gen-X (almost too big) pump at the top of the loop. The only way it keeps its prime is by staying airtight... which it always does... sometimes for days if i keep it off.

While im not a hydro engineer either i think you guys may be talking about different things while using the term "lift". Our loops may be conserving energy by "lifting" up and pushing down, but thats not what Greg was referring to. Unless you can ensure that the loop is perfectly airtight, the intake >of the pump< should be submerged so that it doesnt have to "lift" water to itself if it goes dry.

(Are there pumps that can pull water up to themselves by sucking only air? i havent gotten that far with this stuff yet.)

We just had 2 threads about these pumps last week. Some people mentioned the O ring in the mag drive as being leaky. Maybe you could put some safe grease on that too, it might be leaking air there but not water (yet :roll: ). Another option may be to turn your pump 90 degrees so that the intake is horizontal too, and try to create a "trap" with flexible tubing for the pump to sit in. HTH

 

[O P Ing]

hi.
From the picture, it looks like it is 4" above the water. That's 4 inH2O, or about 0.15 psi. Now, it takes a big hole to leak the air in at this pressure in the time frame mentioned. What puzzles me is that no water leak was mentioned by the original poster...

Almost all centrifugal pump are not self-priming, so it can't pull water up when the housing is filled with air.

 

[Anonymous]

Yeah, I agree that its probably the pump. Even though this is a nice neat set-up, I think I'm just going to put the pump on the floor. That way if there is an air leak most of the tubing would stay flooded and the pump probably would keep its prime.

Also, the only noise my tank makes currently is the hum of the fan- and that pump screwed to the canopy is too noisy.

 

[SPC]

Posted by seven:

hi.
SPC, take a look at a siphon... and imagine it with a impeller in the middle. Now, does a siphon push water?

-I see what you are saying about the siphon seven, so theoretically this would work without the pump there?
Steve

 

[Anonymous]

From the picture, it looks like it is 4" above the water. That's 4 inH2O, or about 0.15 psi. Now, it takes a big hole to leak the air in at this pressure in the time frame mentioned. What puzzles me is that no water leak was mentioned by the original poster...

Mr. Ing- I have to admit that the pump may have been dripping water back into the tank without me noticing....

 

[O P Ing]

hi.
Steve, it is a static siphon, so without the impeller moving, the water won't move... or you are pulling my leg there? :wink:

Dan, if the intake portion of the pump is leaking, it does not drip, but rather, it will generate tiny bubble at the output. There is a way to make this easier to trouble shoot, involving using a holding container between the SS and the pump, and mounting the pump in such a way so that the output is verticle.

+--+
|_ _| <- "ballast tank"
..||
..+==+
..||.....||
..||.....+ = SS
..||
pump

(!$%#ing PHP code! it takes out my space characters!)

 

[bowfront]

Check for a slow drip around the o ring for the impeller cover on the Mag while the pump is running. If so try some silicon grease.

 

[Anonymous]

Where so you get the silicone grease?

 

[SPC]

Seven :wink:

As far as the grease goes, I always use vasoline, is this not cool?
Steve

 

[O P Ing]

Steve, Dan ask you for the lub, not me. I use vaseline on all gaskets, even on water filter canisters. There are some myth about vaseline and silicone-based "gasket" materials that I don't feel comfortable to discuss here :wink: