Nagging Problem

[wallyjar]

Had a pool since 1981 and am really stumped.

Started having some air in pump issues with Pentair variable speed pump. Unit was located about 5 feet from skimmer and about 18" above bottom of skimmer.

Thought I would address along with a pump relocation....Yea now I know that was a bad idea. Moved equipment 25 feet away to get out of sight and mind. When I started back up had a larger bubble in pump basket and would only fill salt cell up about 1/4 of the way...sometimes producing low salt alarm.

When I relocated I used 20' section of pipe so only added one extra joint on each end. Did alls the usual stuff..new oring for basket, lubricated all orings and drain plugs and everything never got better. Pump was cavitating and only way I could stop was to close back the return valve till cavitation stopped. Checked for debris in the impeller but it was clean. Skimmer vbasket clean, flapper working and water level good.

Pump was 5 years old so figured it needed new seal and stuff. Took pump into shop and explained my symptoms I wanted a spare pump so bought a supermax 1 hp and thought I would just install and then fix varliable speed pump and reinstall when I got around to fixing it.

Would you believe same problem!. I was ticked to say the least so I wanted to eliminate anything under the deck. I installed 35' of 1.5" PVC to the suction of the new pump and ran it to the pool and ran it about a foot under the water. So this had to work, right? NO!! Now still about half of pump basket window is still a bubble and salt cell is only about 1/2 full. Hooked back up to underground piping and got the same half window bubble and 1/2 full salt cell. Used shaving cream on every visible joint and fitting with now air leaks.

Simple system two returns, suction from skimmer bottom only all 1.5" pvc.

Pump curve says I should be able to get full suction at 40'. I am at 33'. BIG question. Should a 1 HP pump pull through 1.5" pipe for 33' and push through a 200# sand filter? Is there anyway a super cleaning of the filter help this or am I too far away?

Also, new gauge is high about 25PSI

Thanks,

 

[wallyjar]

Any ideas?

 

[Azgirl71]

Welcome to TFP! I don't have any idea, but we have some great members here who will. Just hang tight and I am sure someone be able to help you.

 

[n240sxguy]

Is this an inground pool? 25psi sounds like a lot of back pressure for what you're describing. Have you back washed the filter? May need to deep clean it. Search for that, and you'll find the instructions for how to do it. Do you have any pictures of your setup?


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[Texas Splash]

Wallyjar, usually when we hear of air in the pump basket or cavitation we gravitate towards air or awkward water flow the suction side. You've been trying your best, but lets re-cap a couple things for everyone watching:
- What was the HP, type and model of your original pump (so we can compare)
- Before you tried the new (temp) pump, and ran a new 1.5" line, was the original suction line size also 1.5"?
- What are the specifics of your pool (type, size, etc)

FYI - My 2HP, 2-speed pump is about 30' away, so I don't think moving your pump 25' away is unreasonable as long as it is sufficient in capacity to move the water freely. Let's see what info you come back with and what others have to say.

 

[Jimrahbe]

So, if I understand correctly, you have bypassed the original plumbing and ran a temporary pipe straight from the pump directly to the pool, but you still can't completely fill the pump basket. But the key point for me is that your SWG only fills half way. ( I assume it is clear and you can see through it). Sounds like something is blocking the return water getting to the cell, like a dirty or broken filter, or something in the return line, like a hunk of PVC from your retrofit.

Not sure of your setup (a pic of the equipment pad would help) but what I would do is take the filter out of the equation. If you have a multiport valve, put it in recirculate, or waste, and see if the bubble in the basket window goes away. Or just plumb the output of the pump directly back to the pool. The pressure gage reads the resistance to the flow going through the filter, so if 25 PSI is higher than normal for you, then that sounds like something is blocking the return water flow. Another thing that I would try, with the filter back in the circuit, is to take the SWG out and turn the pump on and visually see the amount of water getting to the SWG.

Jim R.

 

[wallyjar]

Had 3 HP Pentair variable speed.begining to show bubbles in original location,

One suction line from bottom of skimmer to inlet of pump.

Original suction 1.5" Temporary pipe 1.5"

Only thing I have not tried it to deep clean the snad filter. Will do that before church in the morning and let you know if it helps. If not I will include some pictures after church.

In ground 12x25x5(at deep end) vynal liner

 

[duraleigh]

The problem will not be in the sand. It is for sure a good idea to deep clean it periodically but that is not your issue.

Air leaks come from the suction side and the filter is on the pressure side.

What was your psi with the VS pump running? what was your RPM

What was the psi with the Supermax?

 

[Jimrahbe]

Duraleigh..

Did you catch the part where the OP's SWG was only about 1/4 full and his filter pressure was 25 PSI? It's not like his pump won't prime, he just has a few bubbles in he pump window, these bubbles may be a small suction side air leak, but if his pump is working at all where is the water going and why does this SWG not completely full with water?

While I agree that most "air in the basket" issues are suction side related, it seems that the OP has tried two pumps and has by-passed the original suction side plumbing, but still has the same issue. What else can he do to the suction side?

Thanks,

Jim R.

 

[duraleigh]

Yeah, I missed the 25 psi altogether. Is that for the new pump AND the old? what were they both?

I am struggling with a pump basket 1/4 full and a psi of 25.......that doesn't match up to what I am familiar with. a 1/4 full basket will hardly ever fully prime but will oscillate psi from 0 to maybe 10 PM.

So here is the dilemma. Air gets into the system only from the suction side when the pump is running....it simply cannot get into the pressure side.

OP has ENTIRELY replace two suction sides.....including the pump and air is still getting in????

The only way to go from there is that both times, the suction side had a leak. Probably not in the same place but a leak nevertheless. I can come up with no other conclusion.

 

[wallyjar]

Well, over 30 years with pools and never saw this before. Opened up the filter and the down pipe and laterals were above the sand. The downspout was fused to the multivalve and I could not even turn the downpipe with channel locks. Laterals would not flip up or unscrew to allow me to remove.

I was really tired of messing with so replaced the whole filter and everything is fine. No air in inlet and plenty of flow with pressure at outlert of pump about 10 psi.

I learned filter can keep pump suction from filling the suction side fully. Hard for me to beleve but it is true.

I guess I have a spare pump and I will buy replacement downpipe and laterals and have a spare filter too!

Thanks for the support.

 

[duraleigh]

Did your old filter have a pressure relief valve? Have any idea what happened to your sand?

 

[wallyjar]

Moved pump and filter 25' away from original location(5 feet from pool) Maybe somehow dislodged when we moved?

I would not have believed if I had not seen a new filter fix all problems!!!!

 

[Azgirl71]

Glad you fixed the problem.

 

[wallyjar]

Thanks for responses and suggestions. This was an unhappy pool experience and I am glad it is over!