Best way to run SWCG to raise PH less

[BasicTek]

Hi all,

Prior to my SWCG my PH was almost a constant, but since converting to salt I find myself needing to add 20 to 30 oz of muriatic acid a week. That's not terrible and seems to be running me about 1/2 to 3/4 of a gallon a month. My pool store sells me 2 gallons of 31.45% for $12.50. Anyway I was wondering if running things different would lower the amount of PH that I'm raising.

Currently I run mine at just 8-9% and run the pump 8 hours (9:30 - 5:30) at a fairly low RPM 2,000.
Since I run so low it's feasible I could run the pump half as much time upping my % to 20ish.
I also have a variable speed pump and my solar (which I still use in the mornings a bit but not all day) seems to be happiest at 2,000 RPM's I could set multiple time zones and run at 2,000 in the morning and drop to 1500 in the afternoon, etc


I just don't know how or if any of these changes will affect the increasing PH and figured I'd ask before experimenting. I'd assume less hours would generate less PH but does raising the % set change things as well? Anyway thanks for any feedback.


-Tim

 

[LapPoolMike]

What are your pH targets? Maybe consider only add acid when pH exceeds 7.8, and then only lower it to 7.6? I'm going to try this method for a while. Also, I have not added Borates but I've read they might help.

 

[BasicTek]

What are your pH targets? Maybe consider only add acid when pH exceeds 7.8, and then only lower it to 7.6? I'm going to try this method for a while. Also, I have not added Borates but I've read they might help.

Thanks for the quick reply...

I can't chance the borates because my dog loves licking up the salty water

my PH target is 7.4 but it will pop up to 7.8 at least weekly sometimes in days, I add 20-30 oz muriatic acid back to 7.4. It's not a cost thing but annoys me that I have to add anything weekly or twice a week. Maybe I'll breakdown and buy one of those auto acid injectors but I'm broke from buying a new motor and SWG lol so it will be a while.

Changing my running parameters is easy, and I wasn't sure if that would be an easy way to slow the PH rise.

 

[Perpetual summer]

I know they say every pool is different, My ph hasn't budged in two months, it stays at 7.6. Pool is fiberglass, SWG runs 8hrs a day 2 four hr intervals.

 

[LFrankow]

What is your TA at? I lowered mine a few years back and lowered my acid consumption as well.

 

[elwood58]

Lowering TA is likely your best bet for buffering your pH some. I have the Pentair IntellipH system, and do enjoy only having to handle MA when the 4 gallon tank runs low.

 

[BasicTek]

What is your TA at? I lowered mine a few years back and lowered my acid consumption as well.

Here's my total as I just tested today

FC 7.0
CC 0.0
PH 7.4 (for the next 3-5 days and then it will be 7.8)
TA 80
CH 330
CYA 80
salt 3500

Pretty much everything has been a constant for a couple weeks and apparently even running the SWCG at 8-9% for 8 hours is creating too much chlorine so I'll be adjusting that anyway and I wondered if I could get it to slow down raising the PH in the process. Maybe because it's new (May 4th) it's still raising the PH more, I don't know, but I've had to put in muriatic acid 1-2 times a week since getting it.

 

[Philo]

Just for fun, lower it to 7.2 and see how long it holds.

 

[BasicTek]

Just for fun, lower it to 7.2 and see how long it holds.

I think I've hit 7.2 a couple of times, it does hold a little longer but never more than a week so far, I'll hit it again, as it's only been 6/7 weeks so I don't have all that much history...

 

[Perpetual summer]

My ta=90 was 80 and crept up since opening.

 

[Philo]

I think I've hit 7.2 a couple of times, it does hold a little longer but never more than a week so far, I'll hit it again, as it's only been 6/7 weeks so I don't have all that much history...

If you don't come up with something better......I hammer it down to 7.2 and keep it there, daily for 2 weeks. (full disclosure, there may not be any science to back this up).

Take that..... pH!

 

[BPKlein]

BasikTek,

My numbers are really close to yours. My PH also drifts up. It will stay at 7.5 for a couple of hours at best. It it will hold at 7.8 for about a week. So, I add enough MA to target 7.6, and then don't worry about it. I've chalked it up to just being part of the SWG process of pool ownership.

Bryan

 

[BasicTek]

BasikTek,

My numbers are really close to yours. My PH also drifts up. It will stay at 7.5 for a couple of hours at best. It it will hold at 7.8 for about a week. So, I add enough MA to target 7.6, and then don't worry about it. I've chalked it up to just being part of the SWG process of pool ownership.

Bryan

That's what I'm thinking, have you tried changing the pump run time, and salt generation % to see if there were any different results?

I'm going to try holding it at 7.2 for a bit and see what that does, then I'm going to cut my run time to 4-5 hours and up my % to see what that does. Maybe I should wait before messing with it as it is new, I just like to tinker about with these things. I was just posting here to see if anyone else found changes to help. Ultimately I'll get an automatic acid injector I think, maybe next season...

-Tim

 

[mas985]

The PH rise should be proportion to the SWG on time (i.e. FC production) which is a combination of pump run time with SWG % setting. So unless you change the amount of FC added each day, the PH rise rate will not change no mater what the combination. Since you have a CYA of 80 already, you are probably using the least amount of FC each day anyway so you really can't reduce production.

Also, if you have high TA fill water that you use a lot, the TA will continue to rise so lowering TA may only be temporary.

 

[BPKlein]

Tim,

i haven't experimented because I already have to run the SWG 10 hours a day in the summer heat.

Bryan

 

[BasicTek]

The PH rise should be proportion to the SWG on time (i.e. FC production) which is a combination of pump run time with SWG % setting. So unless you change the amount of FC added each day, the PH rise rate will not change no mater what the combination. Since you have a CYA of 80 already, you are probably using the least amount of FC each day anyway so you really can't reduce production.

Also, if you have high TA fill water that you use a lot, the TA will continue to rise so lowering TA may only be temporary.

Thanks, that's what I was wondering before doddling about, so in effect if I need a net amount of chlorine each day then that amount will cost me a proportionate amount of PH increase no matter how I change the settings to get that amount.

I've never tested my tap water TA but it's probably a good idea for me to run all the tests on it. Lately I've received more than enough rain water to keep my pool full so that's not even in the equation for me right now.