thumping sump

[Annie/Aggie]

sorry about the title LOL
I have just set up a 210g SW tank with a 50g sump. I would like to shut the pump off during feeding but it thumps like crazy for a fair amount of time as soon as I unplug it. My sump tank has double lined walls but I still worry it will break it and it has to scare the fish. It's a submersible pondmaster 2400 or some such name. I felt that adding more rather than less pump than required would be better but it causes an amazing current. Have I connected something incorrectly or should I have the nozzle in the tank pointed any special way?

 

[Innovator]

it's a submersible pump, but is it submersed? I ask because pondmasters are usually able to be connected out of water as well so I am unsure of how it is plumbed on your setup. is the main intake line to the pump unrestricted? it sounds as if you are getting a hammer effect where the pump shuts off and water comes to an abrupt halt, creating a hammer back against the pump...

 

[tecwzrd]

I have the Mag 9.5 and it pumps out a ton of water. I'm sure you have fire hose type pressure with the 24 (2400 GPH). As innovator mentioned most of that noise you hear has to do with how you have it plumbed. Do you use hose or PVC? Do you have ball valves to control flow? A photo would help.

 

[Annie/Aggie]

I'll get you both a picture after work tuesday. I'm pretty sure it's my plumbing as well. I have check valves if that's what you mean by ball valves. Is it?
It is submersed and yes it can go either in or out of the tank but right now it's sitting directly in the sump tank and the PVC goes right up to my tank. The other side comes down into the first half of the sump, it's got a half divider. I was talking with the guy who sold it to me and the only thing he can think of is I have the check valve in wrong. Is this possible? how do I work on it if it just keeps thumping away when I unplug it. It definitely has a fire hose type pressure. How do I just get it to make a decent current only or can I even do that?

 

[tecwzrd]

A ball valve is used to restrict water flow or close the water flow. It's very useful and should be part of every sump setup IMO.

Most check valves have an arrow pointing in the direction of flow. If it's backwards you would get no water or very little water through the pipe. Swing check/ flapper style valves usually do make a little noise versus spring check valves which aren't used in this application.

I assume the thumping stops after a couple of seconds. Does it take longer then that?

Checkout melevsreef.com for more info on plumbing.

 

[Annie/Aggie]

The thumping usually stops after a bit but twice now I was forced to plug it back in as it wouldn't stop. That's why I asked about trying to work on it. I finally got it shut down at 5 am before work. It's been off all day as my 3 little clowns looked exhausted this morning from fighting that current and also the tank backed up on me so they got a fair amount of silt in the water. It was all cleared up this morning so I shut it down. How long is it safe to do this for? Yes I do have a ball valve in the return line and I pulled it out and checked , the arrow is heading in the right direction. Thanks for telling me the correct term, I'm hearing impaired so more than likely missed someone already telling it to me LOL. I do that alot.
So far as I can tell the only thing I'm missing is a tap in the return pipe. I'm going to put one in tomorrow night. It seems I should then be able to turn both sides down at once. Will that mess up the pump at all and is that one way to slow them down? I don't believe that could be causing the thumping though IMO. I'll check that link right away, thanks for the help here.

 

[tecwzrd]

It seems I should then be able to turn both sides down at once.

Not sure what you are saying here.

With the power off to the pump the thumping would only be caused by the water in the pipe draining back to the sump which should last at the most a couple of seconds. As long as it's properly secured there is little worry of it damaging the tank or sump.

With a 210 gal tank there is also little worry that 2000 GPH would cause too much current for your fish. They will rest within the lr if they get tired.

Do you have base/lr in this tank? Is the output from the pump going to more then one outlet?

This is another good link for plumbing. http://www.wetwebmedia.com/plumbingmarart.htm

 

[Annie/Aggie]

ok, what I meant was I could turn both taps to half way and slow the current down, I was wondering how to do that without damaging the pump. Anyway, that link you sent showed me how to do it safely without causing undo pressure on the pump. I've changed the nozzle position and that seems to help as well.
I do have live rock in there and have now seen the fish hide in it. I only got the first fish in it a few dys ago. They don't seem to swim very good without the current as I guess it's what they are used to. They ( clowns) seem to like their food on the move as well.
When I had the ball valve out I noticed it wasn't closing properly so I replaced it, that must have been the problem because it seems there is no more thumping so far. I guess it just kept letting water run back in so it wouldn't stop. I'm going to this new link now.
Thanks