Numbers question

[TanaRayne]

Hi

Took water sample to pool store for numbers check. Here they are:

Free Chlorine: 3.0 good reading
Total Chlorine: 3.0 good reading
Calcium Hardness: 150.0 good reading
Cyanuric Acid: 0.0 below minimum
pH Level: 7.8 good reading
Total Alkalinity: 100.0 below minimum
Copper: 0.0 good reading
Iron: 0.0 good reading
TDS 200.0 good reading

In looking back at my previous sample reports, since 2005, all of my reports have had a "below minimum" on calcium hardness. I have known that, and didn't give it much todo, because I have learned on here that it is not important on the vinyl.

I have only ever added, household bleach, baking soda, borax. I have used the pucks in the inline to raise CYA in the past. To raise the CYA I filled the inline again.

My question is how did the calcium hardness raise? Just curious.

Thanks,
kathy

[chem geek]

Most likely you increased CH as your pool water evaporated and you added more water. If you test your fill water (tap water), I'll bet you'll find that it has some CH. Since whatever CH was in the pool stays in the pool after evaporation, any new water you add will increase the CH.

The only way for CH to drop is to have water physically removed from the pool as with splash-out or backwashing.

The "below minimum" for the Total Alkalinity in the report is incorrect. When using bleach, you can have a lower TA of around 80 or even lower and that will help reduce the tendency for pH to rise. Your pH is currently at 7.8 so it probably won't rise as much, but if you try to keep it at 7.5 and have the TA at 100 or more, you will probably find that it wants to rise and you need to add acid frequently.

I'm surprised they measured no CYA since if you had CYA in the past it won't go away, except from splash-out and backwashing (just like CH) though some people report CYA dropping over a winter.

Richard

[TanaRayne]

Thanks for helping me understand a bit better now.

So, the CH comes from the tap, and as water leaves the pool, from evaporation or splash out, the CH does not leave, it stays. And when I refill the pool, I am adding more CH to the water, making the CH level rise?

I think that's it.

BUT...as I sit here and look through sample numbers. Now I know to take what the pool store says with a grain of salt, and that is why I come here, after I visit the store.

July 2005
CH 30.0 Below Minimum

March 2006
CH 70.0 Below Minimum

July 2006
CH 100.0 Below Minimum

Oct 2006
CH 50.0 Below Minimum

March 2007 (today)
CH 150.0 Below Minimum

From what you told me, I am thinking it will just rise and rise. But by looking at the store numbers, it is a mod podge of up and down.

I am only asking to try and learn.

As for the CYA levels. On the last report, in October, the level was at 10.00, so maybe with the colder months, it did evaporate. I really don't know. I just test and go from there. And alternate seasons, with the inline and bleach.

I was telling someone the other day. I bought this house 5 years ago, and it came with the pool. I knew nothing, and I mean zip, nada about taking care of a pool. I found this site and have read and asked questions. My pool has never been yuck. Now there have been a couple of times, of cloudy water, but always got it back on track, by following recommedations from here.

This is a very knowledgeable group of people.

Thanks for helping me.
Kathy

[chem geek]

I've ever so slightly corrected some things you said below in blue, just to try and make things clear.

Thanks for helping me understand a bit better now.

So, the CH comes from the tap, and as water leaves the pool, from evaporation or splash out, the CH does not leave, it stays. And when I refill the pool, I am adding more CH to the water, making the CH level rise?

The CH will not leave from evaporation, but it WILL leave from splash-out. Evaporation simply removes water but leaves everything that is dissolved in the water to remain in the pool. Splash-out (or backwashing) removes both the water and the stuff in the water.

I think that's it.

BUT...as I sit here and look through sample numbers. Now I know to take what the pool store says with a grain of salt, and that is why I come here, after I visit the store.

July 2005
CH 30.0 Below Minimum

March 2006
CH 70.0 Below Minimum

July 2006
CH 100.0 Below Minimum

Oct 2006
CH 50.0 Below Minimum

March 2007 (today)
CH 150.0 Below Minimum

From what you told me, I am thinking it will just rise and rise. But by looking at the store numbers, it is a mod podge of up and down.
Unless you had some serious splash-out and backwashing from July to October, I would agree with you that the pool store isn't measuring your water very well.

I am only asking to try and learn.

I would suggest you buy a Taylor K-2006 test kit or an equivalent test kit that tests for chlorine using a FAS-DPD drop test and also tests for Total Alkalinity (TA), Calcium Hardness (CH) and Cyanuric Acid (CYA). Don't be intimidated by testing the water yourself -- it really is easy and we're all here to help you through it if you have any questions.

As for the CYA levels. On the last report, in October, the level was at 10.00, so maybe with the colder months, it did evaporate. I really don't know. I just test and go from there. And alternate seasons, with the inline and bleach.

It's certainly possible such a low CYA went away, but if your CYA was truly near zero, you should be losing most of your chlorine in your pool VERY quickly, if the pool is exposed to sunlight. If your CYA is really that low, then you could use your inline feeder (I presume with Trichlor) to add more CYA to your pool. However, with Trichlor you'll need to add more base to your pool, such as Borax, since Trichlor is quite acidic. Your higher TA is actually better when you use Trichlor -- my comments about it being at 80 or so apply to using bleach as your primary source of chlorine.

I was telling someone the other day. I bought this house 5 years ago, and it came with the pool. I knew nothing, and I mean zip, nada about taking care of a pool. I found this site and have read and asked questions. My pool has never been yuck. Now there have been a couple of times, of cloudy water, but always got it back on track, by following recommedations from here.

This is a very knowledgeable group of people.

Thanks for helping me.

Your most welcome and I agree that there are many very knowledgeable and helpful people on this site. It's definitely the best pool web site out there by far.

[CarlD]

"Hi

Took water sample to pool store for numbers check. Here they are:

Free Chlorine: 3.0 good reading

Only if CYA is no higher than 30.

Total Chlorine: 3.0 good reading

That's good because it means Combined Chloramines is 0.

Calcium Hardness: 150.0 good reading

This depends ENTIRELY on whether you have a vinyl or concrete/plaster/tile pool. If vinyl, anything from 0 to 400 is fine and 500 is manageable. If you have the hard stuff, you are too low and need 200-400ppm.

Cyanuric Acid: 0.0 below minimum

Is that a reading of 0 or a reading of 0 below the minimum? Either way you need to confirm that. Outdoor pools should have SOME CYA

pH Level: 7.8 good reading

I personally think that's too high, though technically it's OK. Water will be easier on the eyes, BUT chlorine is far less effective than when it's a little lower. I aim for 7.5.


Total Alkalinity: 100.0 below minimum

While Chem_Geek and I debate on this, I don't think either of us would EVER call 100 "below minimum". I would call it "perfect", he might say it's too high. But if your pH comes down to 7.5, T/A may go down too. As long as you are above 80ppm I wouldn't "fix" it because it's not broken.

Copper: 0.0 good reading

That's fine.

Iron: 0.0 good reading

That's fine.

TDS 200.0 good reading

Meaningless number in 99.99% of all pools with problems, meaningless in ALL pools without problems.

In looking back at my previous sample reports, since 2005, all of my reports have had a "below minimum" on calcium hardness. I have known that, and didn't give it much todo, because I have learned on here that it is not important on the vinyl.

I have only ever added, household bleach, baking soda, borax. I have used the pucks in the inline to raise CYA in the past. To raise the CYA I filled the inline again.

My question is how did the calcium hardness raise? Just curious.

Thanks,
kathy"

[TanaRayne]

Thank you both for being so helpful.

It is a vinyl pool. Needed a skimmer basket and had to go to the pool store, so thought while I was there I would test the water. Kind of like for s&g. (s... & giggles)

Again, thanks
Kathy

[rcabor1]

I do know that calcium hardness is also important if you have a heater... but if not, I would only worry about it being over 400 or so...