Couple of quick questions about PH and Chlorine

[lmhardgrave]

Hello Everyone!

So I have had the pool for about 3 months now and I feel like I am sort of getting the hang of pool care.

Here are my numbers this morning for reference:

Chlorine- 11.5
CH - 450
TA - 70
CYA - 70
PH - 7.5 (I added acid yesterday)
Temp - 68.6

My questions are:

I have to add acid(liquid) about every 3 days. Is that normal? I check the PH at least every other day and it always seems to be hovering around 7.8-8.0.

I am using a SWG and my chlorine was always right about 5.5-6 and I thought I had everything running correctly. But, I hadn't checked it in awhile and this morning I got 11.5 and I did the test twice to confirm. Why did it rise so much? Is a colder temperature the cause? I assume I should run the SWG less to lower it, correct?

Last question.

I have these spots that have popped up in the plaster. Are they algae or something wrong with the plaster? The plaster is only 3 months old so I am not sure what they are but they are pretty unsightly. I would say there are about 6 of them ranging from pea to quarter size. Should I contact the builder or is it something I can take care of. For reference the plaster is Wet Edge primera stone.

 

[Teald024]

Hello, congrats on the new pool.

Hello Everyone!

So I have had the pool for about 3 months now and I feel like I am sort of getting the hang of pool care.

Here are my numbers this morning for reference:

Chlorine- 11.5
CH - 450
TA - 70
CYA - 70
PH - 7.5 (I added acid yesterday)
Temp - 68.6

My questions are:

I have to add acid(liquid) about every 3 days. Is that normal? I check the PH at least every other day and it always seems to be hovering around 7.8-8.0.

Yes, that can be normal for a new gunite pool. Until the surface fully cures, it can make the pH rise. Just keep up with the pH monitoring and drop when needed.

Chlorine- 11.5
CYA - 70
Temp - 68.6
I am using a SWG and my chlorine was always right about 5.5-6 and I thought I had everything running correctly. But, I hadn't checked it in awhile and this morning I got 11.5 and I did the test twice to confirm. Why did it rise so much? Is a colder temperature the cause? I assume I should run the SWG less to lower it, correct?

Yes, you can turn the SWG down to let the FC drop. The colder water, fewer hours of sunlight, and lack of swimming have created less of a FC demand. In a few days you may have to turn it back up to make the FC level off and keep it where you want it.

Last question.

NOPE, sorry, it wont be... lol

I have these spots that have popped up in the plaster. Are they algae or something wrong with the plaster? The plaster is only 3 months old so I am not sure what they are but they are pretty unsightly. I would say there are about 6 of them ranging from pea to quarter size. Should I contact the builder or is it something I can take care of. For reference the plaster is Wet Edge primera stone.

With your high FC, it is probably not algae. But it could be organic if something fell in the pool. Or it could be the start of rust/iron staining. If the rebar is too close to the surface it could be the iron leaching out. The way to tell is to use a trichlor puck. put the puck on one of the stains and leave it there for a minute. remove the puck and if the stain lightens, then it is organic.
Alternately, to check for iron, you can use ascorbic acid (Vitiman C tabs), crushed up and put in a sock. Again put the sock on one of the stains and leave it there for few minutes and give it a rub. remove the sock and if the stain lightens, then it is iron. More details can be found in PoolSchool on Stains . If it's iron, then yes you should talk to your builder.

 

[YippeeSkippy]

Good morning Imhardgrave,

Regarding your pH, when your FC is over 10 the pH test isn't accurate. So let the FC drop and retest. A lot of pools with SWGs find their pH tends to hang out at 7.8, and of course if you're running your water features in the wall daily that will also contribute to a pH rise (aeration).

Are you inputting your numbers into PoolMath to help you monitor your CSI? A pH of 7.8 along with your other numbers might be right in line with a good CSI.

As for the stains- try holding a single chlorine puck on the stain and see if that lifts it. Alternatively, try some crushed Vitamin C tabs in a sock and see if that alters it.
(use different stains for each test if possible)
If the puck makes it go away it is an organic stain, if the Vit C alters it it suggests a metal stain.

Let us know how it goes.

Maddie

 

[lmhardgrave]

Thanks for the replies!

I will do the test as suggested with a puck and with vitamin c tabs.

 

[lmhardgrave]

So I called my pool builder about the spots and he came by today. When he was here we shut off the pump and looked at the "spots", turns out I thought there were about 6 of them but we found over 12 on the floor and the walls while he was here. He didn't have an answer for what they are. So, he is going to have the plaster company come and check them out. Hopefully it is something they have dealt with before...

On another note, I am having trouble getting the chlorine level down. It is still at 12 this morning. I dropped the SWG down from 60%(summer level) on Tuesday down to 10% yesterday. Should I just turn it off completely for a day or two to get the chlorine level down?

 

[mknauss]

Should I just turn it off completely for a day or two to get the chlorine level down?

Sure. Just do not forget to check your FC each day.

You are probably on the cusp of just turning it off for the winter and adding bleach every so often.

Take care.

 

[lmhardgrave]

Sure. Just do not forget to check your FC each day.

You are probably on the cusp of just turning it off for the winter and adding bleach every so often.

Take care.

Thanks for the info. I will continue to check the levels.