MAg7 sucks, doesn't blow.

BigJPDC

New member
LMAO at that thread name.

Finally got all my CL parts painted, taped and glued. Mag7 pump, 3/4" in, 1" out.

105579IMGP5891a.jpg



Bucket test:

105579IMGP5893a.jpg



and . . nothing. What a drag. Hardly any flow coming out of the return pipe. No leaks, which is cool, but even when I remove all the pumbing and drop pump only in the bucket, it only makes small ripples at the surface. Very strong suction on the intake, but almost nothing coming out.

By comparison, this is what my Mag9.5 does:

105579IMGP5786a.jpg


So . . . I have two questions:

1. Do I have a bad Mag7? I only chose it because Melev used one on his CL, and I copied the whole thing from his site, minus the SCWD. Can it drive a 1" CL?

2. Is a Mag9.5 too strong for a CL in a 65 gal?

jp
 

bkwudzjeep

O|||||||O
Thats strange....is it a new Mag 7? Maybe soak in vinegar and clean really well.

I have also read that Mag pump should have double the output size plumbing for max flow.....I would think the 1" should still work better than that.
 

BigJPDC

New member
??? The fittings are 1/2" and it almost pulls the skin off my hand when I hold it over the intake under water.
 

RichConley

New member
Mags really dont like being restricted, moreso on the intake than the output. You're basically starving the pump. Try taking off the intake plumbing and throwing the whole thing in the bucket and see if it works.
 

bkwudzjeep

O|||||||O
Any pump should have as little restriction at the input.....any adjustments/restrictions should always be made at the output.
 

BigJPDC

New member
Rich - I'm going to go try that. I read somewhere that you should go double the intake size before any pipe bends. I wonder if it is that elbow that is the problem. This should take five minutes.

jp
 

AZDesertRat

In Memoriam
Have you tried removing the cap on the end of the suction pipe with the hole drilled in it? You might use a 1" suction strainer instead. It looks to me like you are trying to feed the suction through a series of small diameter holes and they can't keep up with the discharge rate.
 

BigJPDC

New member
well I'll be a mofo. That was it. I took off the intake plumbing and it is putting out what I would have expected when dropped in the bucket.

I was really hoping to hide the pump on the back ledge of the stand behind the overflow tower, which is why that bend was so close to the pump. Any guesses as to how long I should make that input pipe? The Mag9.5 I tested didn't have that long of an input pipe.

jp
 

BigJPDC

New member
no Jeep, not the cap - that actually had holes in it and the same thing rocked on the Mag9.5. I had to unscrew the entire elbow-union assembly from the intake to get any flow.

The bottleneck is the intake elbow, it must be too close to the pump.

jp
 

BigJPDC

New member
Yeah, I think I had things hidden pretty well too, now I think I'll have to split the intake and outlet on opposite sides of the Megaflow tower to allow for the longer inlet pipe.

105579IMGP5858a.jpg



jp
 

bkwudzjeep

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<a href=showthread.php?s=&postid=7508861#post7508861 target=_blank>Originally posted</a> by BigJPDC
no Jeep, not the cap - that actually had holes in it and the same thing rocked on the Mag9.5. I had to unscrew the entire elbow-union assembly from the intake to get any flow.

The bottleneck is the intake elbow, it must be too close to the pump.

jp

Ahhh, now I see....it looks like its pretty well hidden as well...good job!!

What kind of paint did you use? I've read that Sharpie works too, but I'm too afraid to try it....:eek2:
 

BigJPDC

New member
Thanks! I'd be bummed about re-plumbing if all the parts weren't as cheap as they are.

I used the Rust Oleum specialty for Plastic. It chips easily so you have to be careful when doing dry fits and such. I bet I have a couple coats on the parts and will probably dust them again before final install.

I tried the sharpie once, and it looked horrible, and purple. I think I've read more than once that everything in the tank will be covered in coraline in six months anyway, but I wanted everything to blend in.

jp
 

BigJPDC

New member
<a href=showthread.php?s=&postid=7508762#post7508762 target=_blank>Originally posted</a> by AZDesertRat
Have you tried removing the cap on the end of the suction pipe with the hole drilled in it? You might use a 1" suction strainer instead. It looks to me like you are trying to feed the suction through a series of small diameter holes and they can't keep up with the discharge rate.


I wanted to follow up and say that AZ is right here. I got back around to more bucket testing and even with longer lengths between the elbow and the intake this thing still sucks. I changed out the spraybar inlet for one with bigger slots instead of the 1/8" holes and definately saw more flow, although still nowhere near what Melev shows on his site.

I am going to replumb using 1" for the intake, and if that doesn't impress me, I'll get another Mag9.5 for the CL and the Mag7 will go in the salt-mixing vat. It is making clicking noises like it is choking so I am hopeful. Again, the 9.5 with the same setup (unions rock!) blows like a jacuzzi.

I'll report back next week.

jp
 

onegreenray

New member
what i did on my closed loop is attach this to the end of the pipe where the intake is:

cfpt.jpg



then buy one of the screw in intake strainers. screw in so if it gets dirty you can remove it for cleaning:

str.jpg


savko sells both online if you can't find them local.

also i just bought black pvc pipe instead of painting it. a little more expensive but alot easier and faster.
 

BigJPDC

New member
looks good. I found that the strainer that came with the Mag7 fits inside a small piece of 1" pvc, which I then secure inside a 1" coupler. It actually spins in place so I am thinking that if it doesn't turn into a blender then a fish that gets caught against it will easily be able to break loose. I'll get pictures up when I get back to testing.

I am also now leaning towards using the Mag7 for my sump return to the 3/4" SeaSwirl and then expand the CL to include two 1" returns on both back corners, powered by the Mag9.5. Lower GPH in the sump should give me more skimming and the Mag9.5 should give me the flow I want in the tank. I would love to hear what the established reefers here think about that plan.

jp
 
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