TA advice please.

[elesar]

Need PH advice please. Second season with pool and never had to lower PH before.

Water Temp 68
PH 8.2 (Home Depot kit)
PH 8.0 (Taylor K-1000)
I'm not color blind but I'm not real good doing the whole color matching thing.
TC 10
CC 0
Alk 135
CH 180
CYA 45

I prefer not to use Sodium Bisulfate and am looking for MA locally. Have read pool school and am pretty okay with it but would like reinforcement/clarification. Am I lowering PH and letting TA follow or vice versa?
Thanks in advance.
tsw

 

[anonapersona]

Lower pH and let TA do what it will. Monitor TA levels so you are certain how much muriatic acid you need, as that volume is directly related to the pH change you will get. As TA lowers with continued pH adjustments, the amount of acid needed will lower a corresponding amount.

I find that in reading the pH, I try to get a feel for the degree of red vs yellow, don't be swayed by the intensity of the colors, just red vs yellow. See what two values it is definitely between, then guess as to which of the two it might be a touch closer to, or is it square in the middle. You won't be off by too much, as you don't really need to adjust until it is maybe 7.8 or higher, then you will push pH down to 7.5-ish. If you were off a bit, got to 7.3, that is fine, as long as you are not a lot below that you are fine. No need to micromanage pH, just keep it in the range.

You will get better with time at reading the test.

 

[Stuamurr]

Aeration is the suggested method for reducing TA levels, using acid to lower it from 135 will require substantial chemical, it's best to lower the pH with acid and lower the TA with aeration, a good information piece is available in pool school to guide you through TA reduction.

 

[elesar]

Re: PH advice please.

Now PH is creeping up which has never been a problem before. CYA is at 45 so I'm keeping my FC high @ around 10. Have crystal clear water until pool is used. Then gets cloudy, but not opague. Alot of the cloudiness appears to be residue from the Cal-Hypo, which is taking awhile to clear up. PH was 8.0+ last night and 7.8+ today. Added 16 oz MA to bring PH down a tad. Nasty stuff. Should my PH be fluctuating so quickly with my high TA?

 

[dmanb2b]

Aeration is the suggested method for reducing TA levels, using acid to lower it from 135 will require substantial chemical, it's best to lower the pH with acid and lower the TA with aeration, a good information piece is available in pool school to guide you through TA reduction.

Aeration does not lower TA. Acid additions reduce both PH and TA. Aeration simply raises PH without an effect on TA. Repeating that process of lowering PH and TA, then raising PH via aeration, without raisng TA is how you end up with a lower TA.

 

[dmanb2b]

Re: PH advice please.

Now PH is creeping up which has never been a problem before. CYA is at 45 so I'm keeping my FC high @ around 10. Have crystal clear water until pool is used. Then gets cloudy, but not opague. Alot of the cloudiness appears to be residue from the Cal-Hypo, which is taking awhile to clear up. PH was 8.0+ last night and 7.8+ today. Added 16 oz MA to bring PH down a tad. Nasty stuff. Should my PH be fluctuating so quickly with my high TA?

Whoa...let's slow you down here a bit. PH will read falsely high with FC at 10ppm or above. I'm not saying your PH may not be high but high FC may be skewing things more than you are thinking. When TA is 100 or above PH will tend to drift higher, unless you are using trichlor for chlorination, which I do not believe that is the case here.

Couple of questions...why are you maintaining an FC of 10 with CYA at 45?...you should be targeting around 5-6 ppm
Have you performed the overnight FC loss test?
Does the cloudiness appear as you add bleach?

We'll get you through this

 

[elesar]

dmanb2b....... Thanks for the posistive attitude!

FC has been high because of time constraints. Work/testing schedule does not always align with daughter's swim schedule. Sometimes I am away 2-3 days before getting back to maintenance. That and I think my CYA may be a tad higher......still getting experience on reading the CYA test and figure as long as I'm under shock level I'll be safe. The pool never has a chorline odor except one time this year after a large party. FC went down to two so I attributed the smell to "working" chlorine.

Overnight loss has never been greater than one except for the above mentioned large party.

As I think of it, sometimes the water does get a little dimmer after I add the bleach. Since I add in the evening I can't say definatively. However, sometimes the water is not as crystal in the a.m. as it was the night before when adding bleach. However, sometimes the water is "sparkling" clear in the a.m. after adding. I have contributed this to improper dosing. Does this give you any leads?

I have been associating the cloudiness with residual left over from massive cal-hypo dosage earlier in the year. I was informed that using cal-hypo would be acceptable as I was trying to raise CH. But I'm not sure I can blame it all on that now.

Any feedback is appreciated.

 

[Stuamurr]

Sodium Hypo or Calcium Hypo should not cause cloudiness in the water, it may just be due to a high chlorine demand in the pool, adding copious amounts of Chlorine to the pool in one go will not cause any problems unless you are going north 50ppm, but even at that I have read and talked about things like water cooling towers and air conditioning plants that run with FC residuals in the 100-200ppm range without problem.

Apologies for my dyslexic post about aeration, I have just caught up on this thread!

Using Calcium Hypochlorite as a primary source of Chlorine is fine, it's Scotland's no.1 choice for pools, given our soft water with low CH and pH, Using Bleach is recommended as a cheap and easy way of maintaining residential pools as part of the BBB principle.

Your method of raising FC higher than normal to cover more than one day is perfectly acceptable and reasonable, it would be foolhardy not to expect some pool operators to do similar - in fact one pool I look after is only checked fortnightly, usually FC is around 5 when I arrive so I dose enough CalHypo to bring FC to around 10 and then add Calcium Hypo tablets to a chlorine feeder to maintain a residual, with the last week before the next check the chlorine feeder will empty of tabs and the FC level will slowly drop to normal levels, so effectively it runs 11 out of 14 days with a high FC, the owner only wants fortnightly checks so I oblige.

For the record I think you just need to bring your TA down to range and everything should settle in after that.

Regards
Stuart

 

[duraleigh]

Using Calcium Hypochlorite as a primary source of Chlorine is fine, it's Scotland's no.1 choice for pools, given our soft water with low CH and pH,

However, here in the US Cal Hypo can and does cause cloudiness....normally temporary.

Given a high CH pool, (quite common in the desert Southwest) when you introduce Cal Hypo, it is not difficult to reach saturation and have it precipitate out.

 

[Stuamurr]

Using Calcium Hypochlorite as a primary source of Chlorine is fine, it's Scotland's no.1 choice for pools, given our soft water with low CH and pH,

However, here in the US Cal Hypo can and does cause cloudiness....normally temporary.

Given a high CH pool, (quite common in the desert Southwest) when you introduce Cal Hypo, it is not difficult to reach saturation and have it precipitate out.

Hence my inference to soft water and further inference to low CH levels.