Pump Failure

[ASunshine]

I have 2 Little giant 4mdqx-sc pumps that are 18 months old. One pumps the main tank and the other pumps the skimmer. The Skimmer pump motor has failed and needs to be replaced. Was this pump to strong for the job? What pump would you recommend for replacement? How strong does the pump need to be?

[yousuredo]

what skimmer ?
and did you oil it regularly ?

I have the same the presure rated one....

[ASunshine]

I did oil it every month. I wonder if the pump failure is not because the MDQX is not designed to pump under pressure situations. I think but could be wrong that the MDQ is made for this application, ie, skimmer.

[Loverotties]

Dito!

[phishschtick]

Alan are you sure the pump has failed. I thought the same thing when I used a circulation pump for a pressure situation. The head may be too great for it to pump against the pressure but still work fine for circulation. Check the flow on a non pressure situation before you toss it

[phishschtick]

the cut off pressue is 7.4 psi on the 4 mdqx -- that's not much pressure to stop the flow.

[Mafiaman]

Pressure rated or not it could be used for a skimmer.
If it was running your skimmer good for you then it was good.
To bad Andy is on vacation, giving the devil his due, Andy knows pumps.

But using it to run a skimmer was not the cause of failure, this I know.

[phishschtick]

yea but the skimmer outlet may be under water causing the pressure to build up. the skimmer will not work. Alan check to see if the skimmer outlet has been adjusted down into the water where it empties (ie sump) or if the water has risen to cover the skimmer outlet.

I had a skimmer that worked great until I decided to adjust the outlet deeper into the sump water. The pump couldn't go against this pressure. I adjusted the skimmer outlet back above the sump and it worked fine.

A pressure rated pump will typically overcome this situation.

[ASunshine]

The skimmer outlet is out of the water and after 18 months the flow decreased dramaticaly. I disassembled the pump and changed the propeller and axle and there was no improvemnt. This made me think that the motor is failing. Where should I go from here? I am not skimming efficiently now and wonder if I need to replace this pump.

[Mafiaman]

I would replace the pump.
Most of the pumps we buy are priced so if you need to replace the armiture, or field coils you could buy a new pump for just a few bucks more.

[ASunshine]

Which one do you recommend?

[Mafiaman]

The Iwaki MD70 here is the pricing
http://www.myreefcreations.com/iwaki.htm

But I would ask Andy,