water testing

[Divin Dave]

Rain wont have any real effect on the chemistry...Except mybe provide a bit more aeration due to the rain drops splashing in the water.
You will be fine.

And yes, test and just add only what is needed. There is really nothing more to it than that!

It also looks like it might rain Saturday night. How does that effect everything? Or do I just test and add things as needed?

 

[New and confused]

Thanks. The kids (and I) are dying to get in the pool. I talked to a science teacher friend of mine who explained what happens to the muriatic acid when it is put into a pool with high ph. I hadn't realized it turned to salt and water in order to bring the ph down. I feel better about that and kids. One comment you just made about adding the bleach. Why would I want to add bleach if my chlorine is at the minimum? Isn't that what I want? I have been adding it b/c my FC levels have been at zero and I don't want green stuff in my pool. Tonight when I go home I was going to add the muriatic acid to lower my ph and more bleach. Is there anything else I need to do. Yesterday's levels were:
0 chlorine
7.8 ph
320 TA
20+ Cya

This morning my chlorine was better (I can't recall right now, but it was definitely a bright yellow)
7.8 ph

 

[Richard320]

Thanks. The kids (and I) are dying to get in the pool. I talked to a science teacher friend of mine who explained what happens to the muriatic acid when it is put into a pool with high ph. I hadn't realized it turned to salt and water in order to bring the ph down. I feel better about that and kids. One comment you just made about adding the bleach. Why would I want to add bleach if my chlorine is at the minimum? Isn't that what I want? I have been adding it b/c my FC levels have been at zero and I don't want green stuff in my pool. Tonight when I go home I was going to add the muriatic acid to lower my ph and more bleach. Is there anything else I need to do. Yesterday's levels were:
0 chlorine
7.8 ph
320 TA
20+ Cya

This morning my chlorine was better (I can't recall right now, but it was definitely a bright yellow)
7.8 ph

No! You want FC to never dip below the minimum for your CYA level. FC is what keeps algae at bay and what keeps the water sanitary. It gets buffered by the CYA stabilizer, so the actual aggressive chlorine that bleaches swimsuits and irritates skin is less than the unstabilized chlorine in tap water. If you check your FC in the evening, it should be at it's lowest point; the sun has had all day to break it down with UV rays and the swimmers were probably in the pool during the heat of the day. You want to add enough each night so that when you check it the next day at the same time, it's still at or above the minimum.

You will be fighting pH rising for a while due to your high TA; you might find yourself adding acid daily for a week or two to keep pH between 7.2 and 7.8. That's expected, so don't get alarmed.

If you raise the CYA level by adding stabilizer (CYA aka cyanuric acid) to get to 40ish you will lose less chlorine to the sun. However you will need to maintain the FC level higher to account for the CYA. It will still be less aggressive than the tap water, though. An ugly set of circumstances my first year left me with astronomical CYA and no way to lower it, so I was maintaining 24 FC and swimming in it with no problems at all. High FC is not a problem as long as it's proportional to the CYA level. Low FC can lead to algae and the spread of waterborne diseases.

 

[New and confused]

The aggressive tap water you are referring to; is that why my skin is kind of itchy and burning? Just from dipping my hands in the pool to test the water leaves them itchy and a little burning. Will adding the muriatic acid help relieve some of that because of the high ph? Sorry for all of the questions; I am just trying to understand all of the ins and outs.

 

[Richard320]

The aggressive tap water you are referring to; is that why my skin is kind of itchy and burning? Just from dipping my hands in the pool to test the water leaves them itchy and a little burning. Will adding the muriatic acid help relieve some of that because of the high ph? Sorry for all of the questions; I am just trying to understand all of the ins and outs.

High or low pH can both irritate the skin. Low FC can lead to the formation of chloramines which also irritate skin. If you smell that public pool smell, it's not chlorine - it's chloramines.

 

[New and confused]

Hello again - Well its after work and I tested again

Chlorine was 0
and ph was 8.2

So i put in 52 oz of muriatic acid and a gallon of bleach 30 minutes later. I tested after an hour and have the following results:

TC of 9
ph of 7.2
TA of 330

I was going to wait until tomorrow and test. Should I test in the morning or after a day of sun? Should I add stabilizer tomorrow?

 

[New and confused]

I am not sure about cya. I have done it several times and the dot is still visible and I fill the tube up all the way. So I assume my cya is 20+

 

[Richard320]

I am not sure about cya. I have done it several times and the dot is still visible and I fill the tube up all the way. So I assume my cya is 20+

That tube is measured backwards. If the water is to the top, it's below 20.

 

[bridgman]

Chlorine was 0

.... and that's why you need to add bleach when FC is at minimum. FC levels drop fairly quickly over time (unlike the rest of the readings).

I would add enough stabilizer to take it from 15 to 30 as a first step, then check again in a week.

 

[New and confused]

So I tested after work again and the results were:
Chlorine 0
pH 8.2

I added 52 oz of muriatic acid and 1 gallon of bleach 30 minutes later. I waited an hour and tested again. Results:
TC 9
PH 7.2
TA 330
CYA below 20

I was going to test again tomorrow, but should I wait until the end of the day? Should I add stabilizer tomorrow?

 

[bridgman]

Maybe test again in the morning. Once you get everything dialled in, once a day should be fine and evening is probably good.

Add stabilizer whenever you have time. Once it's in and dissolved (which can take a few days) the sun won't use up your chlorine quite as quickly during the day. Something like 25 oz - put it in an old sock and either hang the sock from a stick in front of the return or drop the sock in the skimmer.

BTW I think your pool is actually more like 13,500 gallons than 50,000 gallons, so once everything stabilizes you probably shouldn't be adding an entire gallon of bleach at a time. In the meantime, though, since your Free Chlorine level is dropping to zero in a day I guess you might as well keep doing it since the chlorine is probably killing something in the water.

A half gallon should raise your FC by roughly 3ppm, and a gallon should raise it to 6ppm. Not quite sure how you're getting to 9ppm, maybe the pool is a bit less than 13,500 gallons ?

 

[New and confused]

oops you are absolutely right about the gallons of water. I typed in the wrong number! However, I think I have been putting 15,000 in pool math to get my numbers. Thanks for the correction. Going out to check my numbers now.

 

[New and confused]

Here are my morning numbers:

FC 6
CC 0
TC 6
TA 330-350 (I am not sure I am doing that one right. It takes me 30 drops before it turns an ashy color and then a few more for a light pink)
ph 7.5
CYA below 20

Should I add more muratic acid?

 

[New and confused]

i waited until 11:00 and did a quick check of chlorine and ph
CL .5
PH 7.8

I added 28 oz of muriatic acid and will add almost a gallon of bleach in about 45 min. Then I was going to add stabilizer. we have a lb of it in granule form from our start up kit. I was going to add that to a sock and hang it in the pool near the skimmer? Glad I am home all day to do this. I have to add chlorine every day (as much as pool math tells me) but how long before I am considered "balanced" ? I have a vision system I would like to use to put in chlorine, but the directions say that I need a balanced pool before i set it up. Thoughts?

 

[Divin Dave]

Hi new and confused! Its me again!

You lost 5.5 of FC from 7.30 to 11:21 a.m. this morning. That is way too much loss in such a short amount of time.
The reason you are loosing so much is because your CYA is way too low and the sun is burning it up.
1 pound is not going to do you much good. According to Pool math, you need 72 ounces to get the CYA to 40.
http://www.troublefreepool.com/content/134-recommended-levels

 

[Richard320]

I think you're doing fine!

With that high TA, the pH is going to keep rising fast, although each time you add acid to lower pH, it will take a little less each time and go a little longer between additions. Don't wait for TA to drop to add the CYA. You can go ahead and measure that out into the sock and drop it in the skimmer or hang it in front of a return right now. You don't have to wait for the other stuff to mix.

There is no "balanced" and you're done. It's a constant thing... like laundry. If FC is above minimum for the CYA level and pH is between 7.2 and 7.8, you're there. Since the CYA level will be rising and the pH is needing a lot of adjustment, I'd wait a few days. Once all the CYA is dissolved and you have the pH and FC in range, you're balanced.

Is the "vision system" by chance the Nature2 Vison Pro? That is a mineral sanitizer, and you probably don't want that. Try the search box above and see what other people's experiences have been.

 

[New and confused]

Thanks for the reassurance! I was going to put in a lb of stabilizer pool math said 27 oz by weight 28 oz by vol 70 oz liquid the guy before you (divine dave) said 72 ounces. Am I doing somtehing wrong with pool math. Plus we were going to vaccuum the pool. should I wait to put in the stabilizer?

 

[Richard320]

Thanks for the reassurance! I was going to put in a lb of stabilizer pool math said 27 oz by weight 28 oz by vol 70 oz liquid the guy before you (divine dave) said 72 ounces. Am I doing somtehing wrong with pool math. Plus we were going to vaccuum the pool. should I wait to put in the stabilizer?

No. You must assume you have some CYA in the water already if the sample got cloudy at all. So adding a lesser amount is the thing to do. If you need more CYA later, it's easy enough to add more. If you add 40 CYA now and you're at 18 already.. yowza. So plug 20 in for now and 40 for the target and doublecheck that volume. I don't think your pool is 50,000 gallons. I estimate 13,500 with it filled 48" deep and that would mean 36 oz CYA would be the dose.

If you hang the sock full of CYA granules in front of a return, it will be out of your way when you're vacuuming.

 

[New and confused]

Thanks you rock!

 

[New and confused]

I hate to sound stupid, but how much is that? In pool math I am getting three numbers 36 oz by weight 38 oz by volume and 94 liqud stabilizer. We already have granules (1 lb) I thought I would start with that.