Alkaline & PH very low

[Thailand Steve]

You are doing more work fighting against your automatic pH system then if you turned it off, let your pH and TA settle down, did manual pH testing and adding acid only when your pH hit 8 to reduce it to 7.6.

Stop adding baking soda or soda ash and let your TA and pH drift up.

Ok so I’ve left my pool all night and day without adding soda ash and I’m still under 7 ppm. Thats me trying to let things balance out. Acid pump has been off for days, not had any rain and nobody has swam in the pool.
My PH should have been gradually creeping up but it’s not. I’m really not sure what’s going on??

 

[Bperry]

Ok so I’ve left my pool all night and day without adding soda ash and I’m still under 7 ppm. Thats me trying to let things balance out. Acid pump has been off for days, not had any rain and nobody has swam in the pool.
My PH should have been gradually creeping up but it’s not. I’m really not sure what’s going on??

Quick correction. pH is not measured in ppm. The pH is just 7. If it’s not rising fast then that’s great! You don’t want it rising super fast. What’s the TA like now?

 

[ajw22]

Yesterday you said...

As per previous post:

When my pump came on again this afternoon, I added 2lbs of soda ash. After a few hours I re-tested, now I have 7.4 for acid (digital reading on dousing pump says 7.8) and my alkaline is sitting around 60 ppm.

Today you say it is STILL under 7 (not ppm)?

Ok so I’ve left my pool all night and day without adding soda ash and I’m still under 7 ppm.

What do you mean still?

pH does not drop without help from acid additions, especially not over 0.4.

How are you testing pH? What test kit are you using?

Show us pics of your pH test.

 

[Mdragger88]

Did you turn the pool pump off during this time?
If so get that going & point your jets up to aerate the water to help increase ph.
You say the doser is off but could it still be leaking acid into the pool?

 

[Thailand Steve]

Yesterday you said...



Today you say it is STILL under 7 (not ppm)?



What do you mean still?

pH does not drop without help from acid additions, especially not over 0.4.

How are you testing pH? What test kit are you using?

Show us pics of your pH test.

Yes, still under 7 ppm when I test the PH. My pump stopped at 7 pm last night and started at 7 am this morning.
PH on pump saying 7.48 ppm, manual test kits both look close to 6.8-7 ppm.
This has been the same for past couple of days. I add soda ash and before pump stops in the evening, I’m up to around 7.9 ppm on dousing pump display and about 7.4 ppm on manual test.
Thinking I’m heading in the right direction and the PH will continue to increase (as my acid dousing pump is in the stop position), then next morning it’s back down below 7 ppm when I test.
I’ve now disconnected the discharge hose from the acid dousing pump and put in a blank plug on my circulating line, to see if there was a possibility, acid was somehow still getting sucked from the tank.
If my PH goes up today and still up tomorrow morning, then I will have the answer I guess.
Trying to attach some photos but telling me file size too big.
I’m using a Pentair Rainbow test kit and also a cheap ph/chlorine test kit as back up.

 

[Thailand Steve]

Yes, still under 7 ppm when I test the PH. My pump stopped at 7 pm last night and started at 7 am this morning.
PH on pump saying 7.48 ppm, manual test kits both look close to 6.8-7 ppm.
This has been the same for past couple of days. I add soda ash and before pump stops in the evening, I’m up to around 7.9 ppm on dousing pump display and about 7.4 ppm on manual test.
Thinking I’m heading in the right direction and the PH will continue to increase (as my acid dousing pump is in the stop position), then next morning it’s back down below 7 ppm when I test.
I’ve now disconnected the discharge hose from the acid dousing pump and put in a blank plug on my circulating line, to see if there was a possibility, acid was somehow still getting sucked from the tank.
If my PH goes up today and still up tomorrow morning, then I will have the answer I guess.
Trying to attach some photos but telling me file size too big.
I’m using a Pentair Rainbow test kit and also a cheap ph/chlorine test kit as back up.

Sorry I’m writing ppm again instead of just the ph number

 

[Thailand Steve]

Sorry, I was only ever logging on through my phone but now logged on via my laptop and re-sized some photos.
Alkaline is sitting stable at 60 and I still need to add cyanuric acid but obviously I don't want to be doing that until I get my PH back up.
Is it possible for acid to be sucked from the tank via the dousing pump when the pump is in the stop position? I guess there could be an issue with the dousing pump, allowing this to happen. Certainly was a lot of suction on the dousing pump discharge line when I removed it this morning.
Would explain the constant lowering of the ph, after adding soda ash multiple times.

 

[DavidLast]

Sorry, I was only ever logging on through my phone but now logged on via my laptop and re-sized some photos.
Alkaline is sitting stable at 60 and I still need to add cyanuric acid but obviously I don't want to be doing that until I get my PH back up.
Is it possible for acid to be sucked from the tank via the dousing pump when the pump is in the stop position? I guess there could be an issue with the dousing pump, allowing this to happen. Certainly was a lot of suction on the dousing pump discharge line when I removed it this morning.
Would explain the constant lowering of the ph, after adding soda ash multiple times.

Yes. Dosing pumps may sometimes malfunction and can create a venturi. One way to test this could be to place the suction into a bucket of water and measure the level drop over a fixed time, say 4-8 hours with the dosing system switched off.

Another indication would be a steady decrease in Alkalinity, however, you say it is sitting stable, assuming this is correct, it is unlikely acid is siphoning in via the dosing pump.

I note you are in Thailand. Do you know what the origin of the water is that was used to fill the pool? It may need nothing more than aeration.

 

[Thailand Steve]

Ok as of 5 pm my ph has came up a little bit since I disconnected the discharge line from the acid dousing pump. Now sitting at about 7.2.
Scratching my head though as the alkaline level has dropped again. It’s back to about 40-45!
Not had any rain, acid pump has been disconnected and pump been running 2 x 4 hours today, so what the heck is going on.
Water supply comes from a dam nearby.
As per earlier post, acid level was 7.7 and alkaline was 100 when testing the supply water.
Should be relaxing on a weekend but pool chemical problems is getting me down

 

[Thailand Steve]

how to aerate when the ports are already facing upwards?

 

[Bperry]

Ok as of 5 pm my ph has came up a little bit since I disconnected the discharge line from the acid dousing pump. Now sitting at about 7.2.
Scratching my head though as the alkaline level has dropped again. It’s back to about 40-45!
Not had any rain, acid pump has been disconnected and pump been running 2 x 4 hours today, so what the heck is going on.
Water supply comes from a dam nearby.
As per earlier post, acid level was 7.7 and alkaline was 100 when testing the supply water.
Should be relaxing on a weekend but pool chemical problems is getting me down

I’m not sure I’d trust the TA measurement with kits like that. As long as the pH is 7.2 and rising everything is fine. Go relax a bit and check the pH every day or two and make sure it’s staying above 7.0

 

[ajw22]

If your pH is stable or rising then TA value is less of a concern.

Give your water longer to settle down now that you have the acid removed.

 

[Mdragger88]

how to aerate when the ports are already facing upwards?

So long as you’re getting turbulence on the surface of the water you’re aerating. You can also add more aeration via:
Swimming/splashing around,
Run any water features (bubblers, waterfalls, spillovers etc.)
Use a submersible pump to create a fountain,
Use a return fountain (this is what I do).
Aeration takes time to increase ph in a pool (think days not hours) so be patient.
You’re not in a rush now that ph is in the 7’s.

Aeration - Further Reading

www.troublefreepool.com

For the TA test be sure that you’re going all the way to the endpoint of the test - when there is no further change.

 

[DavidLast]

If the dosing pump is suspect, which it sounds like it is. Can I see a picture of the dosing pump?

 

[Thailand Steve]

I posted pictures of the dousing pump earlier.
I’ve had the pump hooked back up today with suction line coming from a bucket that I marked. With dousing pump in stop position, the level has stayed stable for past 5 hours.
Will leave it like that overnight and see if any change.
Very confusing as the PH has came up good since I disconnected the dousing pump.

 

[Thailand Steve]

If you want more pictures of the suction and discharge lines etc, please let me know and I will do this tomorrow.
All you guys help is really appreciated

 

[DavidLast]

I posted pictures of the dousing pump earlier.
I’ve had the pump hooked back up today with suction line coming from a bucket that I marked. With dousing pump in stop position, the level has stayed stable for past 5 hours.
Will leave it like that overnight and see if any change.
Very confusing as the PH has came up good since I disconnected the dousing pump.

Not really in diconnecting it you may have reset one of the check valves.

Maintenance Manual for the dosing pumps.

I think it would likely need cleaning of the check valves. These are either sides of the dosing head that the tube plugs into.

 

[Mdragger88]

If you want more pictures of the suction and discharge lines etc, please let me know and I will do this tomorrow.
All you guys help is really appreciated

I just wonder if a siphon effect was to blame.
You have a different brand of equipment than most here use but perhaps reviewing some info from one of the more common US ones would be helpful as they likely all work in a similar fashion.

Pentair Intelliph - Further Reading

www.troublefreepool.com

 

[Thailand Steve]

Not really in diconnecting it you may have reset one of the check valves.

Maintenance Manual for the dosing pumps.

I think it would likely need cleaning of the check valves. These are either sides of the dosing head that the tube plugs into.

Really appreciate the advice but that’s way out of my league.
I would need to send it back to the company I bought it from but the last time I done that (2 weeks ago) they told me they had done full service and it was only the sensor . They even sent me a photo of the sensor with big crack in it (was not like that when I sent it to them!!).
I’m guessing they never serviced the pump at all, only done a calibration.
I think I should cut my losses and throw this Chinese stuff in the trash!

 

[ajw22]

I’ve had the pump hooked back up today with suction line coming from a bucket that I marked. With dousing pump in stop position, the level has stayed stable for past 5 hours.
Will leave it like that overnight and see if any change.

I would stop tinkering and leave the dousing pump out of the pool for a while.

Get some experience with testing and tracking your pH and TA without it being effected by any outside influences.

Record all your test results in PoolMath

Very confusing as the PH has came up good since I disconnected the dousing pump.

What is confusing that your douser system was continuously adding acid and causing your pH and Ta problems? That is why we don't recommend those system. You never know when they go haywire.