WhT damage can high alkalinity do to spa motors?

Loopman

New member
Jan 30, 2019
4
North ca
#1
My spa mechanic said my 2 pumps stopped working from high alkalinity. He pointed to white powder on motor as evidence. I do the chems myself and when the alkalinity gets high 200 I change the water.
I use chl tabs and add soda ash to keep it from getting acidic.
 

JamesW

TFP Expert
Mar 2, 2011
13,074
#2
Alkalinity has zero effect on motors. The white powder is aluminum oxide from corrosion probably due to a seal leak.

Pool or spa water never makes contact with the motor other than when the seal leaks.

High CSI can cause scale in the pool or spa or the associated plumbing and equipment.

Keep the CSI between -0.3 and 0.0 for best results.
 
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Loopman

New member
Jan 30, 2019
4
North ca
#3
Alkalinity has zero effect on motors. The white powder is aluminum oxide from corrosion probably due to a seal leak.
Thank you, I didn’t think so , the spa companies are always trying to sell their own chems, which was why I was skeptical, also the fact that it was 2 pumps at the same time.
 
Likes: Hogman
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Loopman

New member
Jan 30, 2019
4
North ca
#5
Alkalinity has zero effect on motors. The white powder is aluminum oxide from corrosion probably due to a seal leak.

Pool or spa water never makes contact with the motor other than when the seal leaks.

High CSI can cause scale in the pool or spa or the associated plumbing and equipment.

Keep the CSI between -0.3 and 0.0 for best results.[/QUOT
What happened to the motors?

Will they not turn on at all?

Is there water in the equipment compartment?
i think I starved them of water. The water level was low, this was a week or 2 before they failed. They made a slightly funny noise after that. I assumed since they ran after the low water incident they would be ok. I would have expected them to fail immediately.
 

JamesW

TFP Expert
Mar 2, 2011
13,074
#6
Running dry can damage the seal, especially if the seal is the lower quality type of seal.

Then, water leaks out and gets in the motor, which usually corrodes the bearings and the motor seizes.

If the motor gets really soaked, it can short out the motor.

Is there water around the pump?

When you replace the seal, there are 3 types, plastic, carbon and silicon carbide.

Don't use the plastic. The carbon is the minimum you should use. The silicon carbide is the best, but it's expensive.

If you can find silicon carbide for a good price, that's the way to go. Otherwise, get the carbon, which is usually labeled as "ozone/salt" compatible.
 
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Loopman

New member
Jan 30, 2019
4
North ca
#7
Running dry can damage the seal, especially if the seal is the lower quality type of seal.

Then, water leaks out and gets in the motor, which usually corrodes the bearings and the motor seizes.

If the motor gets really soaked, it can short out the motor.

Is there water around the pump?

When you replace the seal, there are 3 types, plastic, carbon and silicon carbide.

Don't use the plastic. The carbon is the minimum you should use. The silicon carbide is the best, but it's expensive.

If you can find silicon carbide for a good price, that's the way to go. Otherwise, get the carbon, which is usually labeled as "ozone/salt" compatible.
Thanks. I’ll look at everything more closely tomorrow