New DIY Pool Construction - Pressure Loss Question HELP

[TW Pool]

Hi all. I am building a new IG pool in the Houston area and have a plumbing questions.

I had my pool plumbed about 3 weeks ago, just before I went on a vacation/work trip. We've had a ton of rain while I was gone (just putting this out there in case it means something), but nothing has been done on the pool while I have been away.

I have 2 pumps for my pool...

1 pump is a waterfall pump that has it's own return and goes straight to the sheer descent (no filtration). It was pressurized to 20 PSI and is still at 20 PSI.

The main pump (for pool, spa, 2 main drains, 2 skimmers, all returns, and bubblers) started at 25 PSI, but is now a little over 16 PSI. It has slowly dropped. Is this a concern?

My initial thoughts are that a 40% drop in pressure is bad. However, I'm not sure if some pressure might leak out the skimmers, etc. if they aren't capped off and this is normal.

Can someone please let me know if I should get the plumber back out? Or is this pretty typical?

Thanks!

 

[Bama Rambler]

How long did it take for the pressure to drop?

If it took several days then it's probably not a problem, but if it occurred overnight, it's certainly a problem.

 

[TW Pool]

It has been a slow drop. Going on 17 days or more now and I have watched it slowly go down. If both were the same, I would think nothing of it, but the feature pump is holding at 100%.

Of course, that system is still locked solid. I'm not sure if the main plumbing is sealed. I have to assume the skimmers and possibly the blower could leak pressure.

I just want to make sure I get any problems fixed (if there are any) prior to laying down my decking!

 

[Bama Rambler]

If it's taken it 17 days to drop, I wouldn't be concerned about it. A plug or temporary cap could leak a tiny amount and cause that.

I'd probably pressurize it back up and see how much it drops in 48 hours.

 

[TW Pool]

Thanks Bama!

 

[prs]

I think your main pump is a variable speed so the obvious question is it still running at the same rpm? If so, for the pump pressure to drop either some restriction was removed from the return side of the pump (eyeballs being forced open, or maybe line to spa opened?) or the suction flow has been reduced. Do you see bubbles in the pump basket, or do you hear the sounds of cavitation at the pump? What has happened to the watts of the pump? If they dropped at constant rpm that would indicate reduced flow, if they increased that would indicate higher flow.

 

[TW Pool]

I think your main pump is a variable speed so the obvious question is it still running at the same rpm? If so, for the pump pressure to drop either some restriction was removed from the return side of the pump (eyeballs being forced open, or maybe line to spa opened?) or the suction flow has been reduced. Do you see bubbles in the pump basket, or do you hear the sounds of cavitation at the pump? What has happened to the watts of the pump? If they dropped at constant rpm that would indicate reduced flow, if they increased that would indicate higher flow.

The pump isn't running. We are in construction and have the pipes sealed to make sure they aren't damaged by other subs. However, the pressure loss that has occurred, has all happened when no subs have been out since the plumber (long work/vacation trip).

 

[prs]

In that case a miniscule loss of air or water could cause that pressure reduction, I wouldn't be concerned about it at all.

 

[TW Pool]

Still holding at just above 16 - so I am guessing there could have been a little settling going on. Thanks for the replies!

 

[WardL]

The extent of my knowledge on this is that I have watched my own pool be built. Given that qualification, why would you not expect your piping to hold pressure for as long as it is being tested? On my pool they pressured up the piping and kept it pressured up until it was time to install the rest of the equipment. In my case, this was about two months. I think it would be prudent to pressure up the system to maybe 50# and look for the leak while you can still get at all the piping. Get some soapy water and look for bubbles. It will be a lot easier now that later. OK, so your leak is a slow leak now, how do you know it won't get worse? Once you find the source of the leak then you can decide if it is no big deal. My two cents.....