New Member. PH gone wild!

[KentC]

I have been scouring your website off and on for weeks and have tried to follow every piece of guidance I could glean from your great pool school, pool math and similar issue post responses.

My situation: I have a 7 year old, plaster pool in east central Florida, no water features, inside of a screen enclosure. My acid demand has gone from a cup per week to 6/wk in the last year or so! Even when I completely shut off the CL generator for a couple days, PH still goes up. I used to be able to check the pool weekly and results were pretty stable.

I had been using a 2yr old K-2005 test kit but recently updated to a new K-2006 with no noticeable changes in results except for CYA (see below). I record all test results and chemical additions. Latest results:

FC 5.0
CC <0.5
PH 7.5
TA 60
CH 370
CYA 80
Borate ~30 Need more borate after lower and refill (see below)
Salt 3700
CSI = -0.47
PH seems to go up about .15-0.2 per day
Water is crystal clear. I certainly can tell heads / tails on a dime at the bottom of the pool.

CYA. My old CYA reagent had an expiration date of 08/20 and the new kit date is 04/21. I had used the old kit to adjust from 50 to 80 to match TFP recommendation. With the new kit, I got 120! Retested with remaining old reagent and got 80! Called Taylor and they said both batches tested “perfect” at the factory but to go with the newer reagent results. This forced the lower and refill with about 3000 gal. Salt and CH are back where I had them and am ordering more boric acid to get back to 50.

How much aeration does it take to dramatically raise PH? I have a “small” suction side air leak that is minimally worse than 3 or 4 years ago. Most of the time I can easily count the 1/8” diameter bubbles coming into the pool. A lot of the time there are no bubbles and occasionally they come in in bunches but just doesn’t seem like much air. It doesn’t seem to make any difference whether solar heat is on or off, SWG on or off, drawing from skimmer or main drain or both. I have trickled water over all above ground suction side joints and the pump basket with no discernable change. I can see small bubbles coming into the basket from the inlet, but not a “stream”. I have reviewed the “How to: Suction Side Air Leaks” but haven’t taken anything apart or done any digging yet. All I can hear when I get close to the valves is water flowing and pump vibrations. The pool isn’t losing any water beyond evaporation.

None of the adjustments made to get to TFP recommendations seem to have changed the acid demand trend. I’d sure welcome any guidance that could at least stop the rise in acid demand.

Thank you.

 

[Oly]

Have you tested your fill (tap) water for TA and pH?
How do you top off your pool to make up for evaporation?
Do you have an auto-fill or do you top it off yourself each time. How often?

 

[KentC]

I top off manually. Hadn't added water since mid July until the refill. Refill water is PH over 8+ and TA is 60 with the softener bypassed.

 

[KentC]

This morning incoming bubbles were much worse so I had my wife watch bubbles while I sequentially ran water over all above ground suction side components. We thought we had something when I pushed water up under the pump basket lid so I removed the lid and cleaned the seal and mating surfaces and coated the seal with Lube Tube seal lubricant. Also did the basket drain for good measure. The bubbles were worse! I went to the local pool store, paid an outrageous price for the top basket seal, lubed it up along with a new drain plug & seal. Still lots of bubbles. Unless I suddenly have concurrently worsening underground leaks / breaks in the skimmer and main drain suction lines, I should be able to either find the issue above ground or isolate the leaks by shutting off one or the other of the draw sources, correct? I am totally baffled. Suggestions?

 

[mknauss]

Can you post pictures of your suction side set up?

Use plastic wrap around connections, valves, etc.

 

[KentC]

A couple pics of suction setup

 

[mknauss]

Start by isolating different suction paths using your valving to see if the bubbles change. Check your skimmer weir to be sure it is not stuck. Then start with the union into the pump. Use plastic wrap around it. Then work out. Lots of trial and error. Concentrate on anything you changed, opened, etc.

 

[KentC]

I wrapped everything I could get wrap around, wetting the pipe before applying each piece of wrap to improve adhesion between the fittings, etc and the wrap. Hard to have high confidence in the wrapping around the valve. Couldn't really get behind the union collar next to the pump, so I took the collar loose and wrapped the joint directly (had had it off earlier to see if the joint was sitting flat). No change at all. Weir is good. Turning off the skimmer or the main drain don't make a difference. Seems like it has to be at the skimmer / main drain diverter valve or piping to the pump or a part of the pump. Ever see a problem at the joint where the two halves of the pump fit together?

 

[mknauss]

Well thats a bummer.

On your pump question, let's call in @JamesW for advice.

 

[proavia]

On the suction side air leak.... you said you opened the union just before the pump. Did you thoroughly clean all the mating surfaces? Clean and lube the o-ring? Checked to be sure the o-ring was seated properly in the groove? Check to be sure the threaded pieces were clean and were threaded together properly?

 

[wireform]

I read somewhere once there was a problem with air such as this and they questioned the OP if all returns had eyeballs or jets. If I remember correctly the explanation was if the return lines didn't cause enough back pressure on the system it can cause air like you see on the suction side of things. Just a thought. On the return line after the SWG you have a valve. Maybe close off one or the other a bit to see if it makes any difference. You also have a "glue less" look to the plumbing. Possibly leaking from them. Saturate the ground where they come up before the pump while pump is running. It may be below right there. Had that not long ago in a below surface connection.

 

[JamesW]

The place where the two halves of the pump meet is under pressure. So, it won't be related to a suction issue.

Try watching the various suction joints while someone turns off the pump.

When the pump turns off, there's a brief moment where back pressure exists and water can leak out of the joint.

Alternatively, try pushing water from the skimmer through the pump using a garden hose while the pump is off. It's not a lot of pressure, but it can be enough to identify a leak.

You can partially close the returns to create more pressure on the suction side but don't put a lot of pressure on the system.

Don't go over 10 psi.

 

[duraleigh]

Suction leaks are hard to find and yours sounds very minimal.....even harder to find!

If you turn the system of for maybe 4-6 hours, does it still hold prime? If it begins to drop prime, you may be able to hear the air seeping into the leak as the water drains back to the pool. No reason to look at ANYTHING on the pressure side.......that's not where the leak is.

 

[KentC]

Thank you to all who have responded. I have more ideas to try today.

In response to Proavia: I did not open the union just ahead of the pump basket as that would require dismounting the pump. I did try running over the joint with the collar off and out of the way and checking change in bubbles and also tried wrapping the union with plastic wrap with and without the collar. Still no change in bubbles. The treaded parts are good and feel like they smoothly pull the joint together but is doesn't leak even without the collar on.

In response to Wireform: All eye balls are in place. Pressure at the filter inlet is approx 10psi at 2300 pump rpm. I had the same thought about saturating the ground since we haven't had much rain since early August but didn't get any change by running the hose there for a few minutes yesterday. I'm still convinced it has to be between the skimmer diverter / main drain diverter valve and the pump given that switching between the two draw sources doesn't change the amount of bubbles.

In response to JamesW: Thanks for keeping me from having to disassemble the pump! I had checked for any drops of water after shutting the pump off but found nothing. I like the idea of pressurizing the suction side with a garden hose and will try that today.

In response to DaveS: When I started this post, my real concern was, and still is, the ever increasing acid demand and at that point I felt the amount of bubbles was minimal. However yesterday, whether coincidental or because I started messing around to see if I could find the source of the suction side air leak, the bubbles increased dramatically. I don't have a frame of reference to know if the current bubbling level could cause high PH levels or not. I do know it needs to be addressed either way. Still need to figure out the PH issue. Oh yes, the pump holds prime overnight just fine.

One new point, late in the day yesterday I played around with different pump speeds and at 1000 rpm bubbling virtually stops. The pressures indicated at my filter inlet and pump speed don't seem to correlate will with the pump curves in the manual, but I have to guess that I'm still pumping about 20gpm. I can let it run here but won't work for the heaters. I normally run 2000 rpm for the solar to work well. I'm going to be gone for 8 days starting Tuesday so I'd like to figure this out in the next 2 days but if not, I can just leave it at 1000 rpm. Thank you all

 

[Jimrahbe]

Most of the time I can easily count the 1/8” diameter bubbles coming into the pool. A lot of the time there are no bubbles and occasionally they come in in bunches but just doesn’t seem like much air.

Kent,

Maybe I just missed something, but that sure sounds like the same bubbles I get from my SWCG...

They are there when the cell is producing chlorine and not there when the cell is resting.. They often come in puffs or bunches..

Thanks,

Jim R.

 

[duraleigh]

That you can hold prime for extended periods means that leak is pretty small. I forgot......did you slowly run water over the pump basket lid with the pump running?

A leak as small as you describe will have NO EFFECT on your pH to speak of......it's too small. I can't answer why your pool seems to ask for more acid but it is not because of that tiny suction leak.

 

[KentC]

At JamesW suggestion, I tried pressurizing the system with a garden hose from the bottom of the skimmer and from the pool cleaner port and never could develop more than 3-4psi at the top of the filter. Just don't have a fitting to get good enough seal I guess. I even tried shutting off supply back to the pool. Not sure why the builder put in a diverter valve that allows shutting off supply to the pool. In any case, didn't get a drop of a leak anywhere we could see.

For JimR: I wondered about the SWG bubbles also but made no difference with cell off or on. Also, bubbles are much larger and more numerous in the last couple days when I run a normal pump speeds.

For DaveS: Yes, I ran water on the pump basket lid and all other accessible suction side components several times with my wife watching the bubbles.

Definitely have two mysteries.
1)Why all of the bubbles? I'd be ready to start digging but I can't even seem to isolate the suction side air leak to one draw source or the other! Is there any place in the system that might create a venturi effect using water flow to draw in air but not have a leak when the system is off or externally pressurized? Sounds preposterous, but I'm really grasping.

2) Why is PH climbing? Everything seems very stable and at or near TFP recommended levels except for increasing PH.

 

[JamesW]

3 psi should be enough to identify a suction leak.

 

[duraleigh]

I can answer #2..........there is a tendency in almost every pool for the pH to climb.......some worse than others. It's the nature of the beast.

I can't answer #1 but I can tell you this.......most everyone assumes their suction side leak is underground and while it can be, it almost never is.

 

[proavia]

Thank you to all who have responded. I have more ideas to try today.

In response to Proavia: I did not open the union just ahead of the pump basket as that would require dismounting the pump. I did try running over the joint with the collar off and out of the way and checking change in bubbles and also tried wrapping the union with plastic wrap with and without the collar. Still no change in bubbles. The treaded parts are good and feel like they smoothly pull the joint together but is doesn't leak even without the collar on.

If you unscrewed the collar near the pump inlet, you opened the union. You said the bubbles had increased on Saturday morning. What did you do between your initial post and the Saturday morning post? No telling if you got a tight seal over the union or not - you may want to check that the union o-ring is clean and lubed. Did you check just below the level of the rocks in the first pic in post #6 to see if that valve may be sucking in air? How about around the valve lids or where the handle shaft comes up thru the lid?

Do you have any shaving cream? You can try putting that on the joints and seeing if any gets sucked in.

Is the water level at least 1/2 way up the skimmer opening? Looking into the skimmer from above, what does the water flow look like... gentle water flow or crazy cyclonic flow or .... ?