closed loop problems

[leebo_28]

just finished a closed loop on a 90AG RR tank(had the back drilled with two intakes 1 1//2)
My question is...my pump (aquasea3600sp) makes an awful humming , almost rattling noise... but when i give the drains a little air the pump quiets down to a mere humm....but then i have tons of bubbles in the tank! any suggestions would be appreciated!
p.s. jus freshwater in the tank now for testing
p.s.s could it be cavitation??

 

[jmait769]

but when i give the drains a little air the pump quiets down to a mere humm

Could you give a better description of the closed loop? I ask because normally, on a closed loop, you do not want any air in the system. It sounds like you are draining into the sump then back up with the pump like a return? Maybe a picture of your setup would help. I based mine on Melev’s <a href="http://www.melevsreef.com/closedloop.html" target="_blank">Closed Loop</a>

Jay

 

[Reeses]

Most of the time the first time you prime and fire up a pump, it's because it hasn't work out all the air in it yet. My iwaki's are like that.

 

[davidryder]

Why are you introducing air into the line? Reeses is correct also, the pump doesn't move nearly as much water when air is mixed with it...

 

[leebo_28]

how do i post pics?

 

[jmait769]

Here is a good thread on how to upload your photos into Photobucket and then post them here on RC: <a href="http://www.reefcentral.com/forums/showthread.php?threadid=531326" target="_blank"> How to post a pic using a free service such as Photobucket</a>

Jay

 

[Reeses]

home page
link on left labeled "photo gallery"
find "upload photos" on top right.

 

[leebo_28]

ok... got two at my gallery!

 

[davidryder]

Nice setup... again - why are you introducing air into the line?

 

[leebo_28]

I am not trying to put air in the drain...i just happened to not have a sealed cap on it yet ...so i turned the valve(blocking the hole over the intakes) on a little..and the pump got a lot quieter...but is adding bubbles too the tank. I just wanted to know if the pump is cavitating , would it make the "loud" noise it is making or like Reeces said...might be trapped air.

 

[leebo_28]

i read that you have to have so many exit drains or it will cavitate the pump..but can't find it anymore

 

[connecticut cichlids]

tagging along on this one...From the looks of the photos, there seems to be big enough drains into the pump. Is that pvc that your using for the intake, the suggested diameter? I see that your discharging through the back, and over the top...I'm no expert, but there seems to be alot of 90 degree turns in there-JMO...my vote is for cavitation, or poss. bad pump.

 

[davidryder]

The pump gets quiet because it doesn't spin as fast when air is mixed with the water.. mine does the same thing if I take the cap off the top.

 

[leebo_28]

<a href=showthread.php?s=&postid=9766202#post9766202 target=_blank>Originally posted</a> by connecticut cichlids
tagging along on this one...From the looks of the photos, there seems to be big enough drains into the pump. Is that pvc that your using for the intake, the suggested diameter? I see that your discharging through the back, and over the top...I'm no expert, but there seems to be alot of 90 degree turns in there-JMO...my vote is for cavitation, or poss. bad pump.

yes it's 1 1/2 inch pvc pipe into the bulkheads...then pvc flexpipe into the pump.
I have great flow(maybe too much) when I power it up . Thanks for the info everybody...if it is cavitation...just add more drains?

 

[Reeses]

IMHE, A loud rattle us usually an indication of two things:
1. Air stuck in the pump that usually remedies its self
2. A broken impeller

Possibly in the case of (only) a loud hum:
3. Pump has most likely not been secured tightly
4. Lines are not secured properly, and causes a vibration
amplification.

I'd go ahead and seal that cap (mine's a screw on w/ teflon tape) and see if the elimination of it pulling any air fixes it.

It looks great, btw. How did you attach the suction cups?

 

[leebo_28]

<a href=showthread.php?s=&postid=9766295#post9766295 target=_blank>Originally posted</a> by Reeses
IMHE, A loud rattle us usually an indication of two things:
1. Air stuck in the pump that usually remedies its self
2. A broken impeller

Possibly in the case of (only) a loud hum:
3. Pump has most likely not been secured tightly
4. Lines are not secured properly, and causes a vibration
amplification.

I'd go ahead and seal that cap (mine's a screw on w/ teflon tape) and see if the elimination of it pulling any air fixes it.

It looks great, btw. How did you attach the suction cups?

SUCTION CUPS???

 

[leebo_28]

thanks reeses...there are no suction cups as of yet(fingers crossed)
I am hoping it is like you said...just working the air out of there!
I noticed a pinhole leak in one of the threaded fittings also , so maybe I'll just button her up and work on the rest...thanks again!

 

[REHEM]

You might check all of your PVC connections for a tight, cemented seal. Look for any signs of moisture at all connection points. Even a needle sized hole can allow air into the lines.

Also, you might try plugging in and unplugging; plugging in and unplugging a few times. This will usually push out any remaining air trapped in the pump.

Sorry-that's all I've got...

 

[REHEM]

<a href=showthread.php?s=&postid=9766310#post9766310 target=_blank>Originally posted</a> by leebo_28
SUCTION CUPS???

(I think they're mistaking the bulkheads for suction cups as if being used to secure the PVC to the back of the tank.)

 

[Reeses]

Yup, I'm an idiot, and that is the SECOND time today I thought I saw something that I didn't.
:lol:
I promise I'm not THAT much of an idiot, my tank is undrilled and I didn't look at your front view pic you posted closely.