Where did my Calcium Go? And other questions....

[tunacan]

I hope everyone is having a great summer. My pool has been amazing all season thanks to lots of help from everyone here.

I have a few follow up questions and would appreciate any help:

Let me start by mentioning my pool looks and feels great. Sparkling water, no signs of algae, and the water feels soft on the skin. This is all new to me after 6 years of fighting my pool. Now the questions...

About a month ago I got all my levels within the suggested ranges. I've been testing FC and PH daily but hadn't done a full set of tests in a while.

6/15

TA: 110
CH: 270
CYA: 35(ish)

7/15

TA: 50
CH: 140
CYA: 30(ish)


* What caused my TA to drop so far, and where did my calcium go (I had added about 20 pounds earlier in the season)?


I should mention that I use bleach every night, and I feel like I'm needing to use too much acid. PH is constantly climbing on me. I would estimate that I add about half a gallon a week. We do use our jacuzzi a lot. If we have the kids over, the jacuzzi is running all day long - perhaps that's enough to keep bumping PH?

I'm assuming I'll add baking soda predisolved to increase TA, correct? And simply add more calcium? Can I adjust both of these on the same day or will that cause a cloudy mess?

Also, I use about a gallon of bleach per day on my 15,000 gallon pool. It seems like a lot, but I'm new to this. Is that out of line for a pool that's in the sun all day long in socal? Is there an ideal CYA/FC relationship that maximizes cost efficiency? Finally, the cheapest I can find bleach is at costco for about $2/gallon. Any suggestions on finding cheaper bleach? I've read elsewhere on this site about negotiating with a laundermat - anyone have experience with that?

Thanks to all in advance!


Ron

 

[jblizzle]

Since everything went down, I have to wonder about your fill water. If it is very soft with low TA, with a lot of water replacement those could go down ... Although the large drops would be more indicative of a water leak with an autofill making the problem.

Our maybe I am pessimistic since all we usually see on the board are problems

Posted with Tapatalk ... sorry if I sound short ... hate typing on phone

 

[tunacan]

Hi Jason,

Thanks for your reply. My fill water actually has a TA of 120 thus the confusion. Does muriatic acid or bleach lower TA? I add water every weekend and haven't noticed anything unusual. Thanks again.

Ron

 

[tunacan]

Jason,

I hope I'm not the first person to do this. Right as I submitted my last post it occurred to me that the 50 TA vs 120 TA was pretty close to the ratio of 10ml to 25ml. I'm pretty sure I used the wrong sample size, which also explains where my calcium went. Hopefully that provides a good laugh. I'll test and post again tomorrow. Thanks!

Ron

 

[jblizzle]

Better a testing error than a real problem

Fyi, when you lower pH with acid, it will also reduce the TA.

Posted with Tapatalk ... sorry if I sound short ... hate typing on phone

 

[tunacan]

Thanks, Jason - I did not know that about acid lowering TA over time.


How about the other part of my question:

1. Is there an ideal CYA/FC level that maximizes cost efficiency? Does it sound reasonable that I'm using about a gallon of bleach every day in a 15K gallon pool?

2. Where can I find bleach for less than $2/gallon? Buy in bulk?

3. Finally, why am I constantly needing to add acid (about 1/2 gallon per week)? Is this normal?


Thanks!

 

[Melt In The Sun]

1. Not really an "ideal"; increasing CYA to 50 or 60 from your current levels should help you use less FC each day. The flip-side is that it's more difficult and expensive to shock with higher CYA levels.
2. Good luck.... Just check around with your local pool stores for "liquid chlorine" prices.
3. Spa! Any bubbles will raise your pH a little, and a ton of bubbles will raise it quickly!

 

[tunacan]

Thanks for your reply, Jason!


1. So as long as I don't have to shock (algae has not been a problem), more CYA will reduce my bleach needs? In other words, it will take longer for FC to lower from 10 to 5 @ 60 CYA than would from 7 to 2 @ 30 CYA, correct?

1a. That raises a separate questions. I'm raising my FC to about 7 or 8 each evening. I have not shocked at all this season. MY water looks amazing, so is shocking still necessary occasionally?

2. Crud!

3. Ok that makes me feel better. So a spa running for an hour or two on average everyday will probably require the use of a couple of gallons of acid every month?

3a. Another related question. I generally wait for PH to rise to about 8 then drop it down to about 7.5. Is there anything wrong with doing it this way? I'm just being lazy, so let me know if it's better to drop it daily. Also, I add acid by slowly pouring in front of a return line...is the correct method?

Thanks again!

 

[jblizzle]

I did not write the last response (although we are both in Tucson)

1. Yes. With higher CYA, you should loose less FC each day due to the sun
1a. You want to raise the FC high enough that it NEVER drops below the minimum in the CYA/Chlorine chart before the next time you add. Ensuring this, you may never have to go through the shock process again. If you start seeing a higher FC loss than expected or cloudy water, running the OCLT can determine is something is hiding in the pool. If you are expecting a high usage, it is fine to bump up the FC a little higher before (and after) the party to ensure you do not drop below the minimum.

3. Some people find they have to add acid every couple days. With the jets running each day, you will certainly have to keep an eye on the pH rise
3a. It might be a little better to not let it get above 7.8, but daily should not be needed. That is the correct method.

 

[tunacan]

Thanks for checking back, Jason.


1. Cool. I think I'll bump it up to 50 CYA see how much bleach I go thorugh in a week and then perhaps go to 60 CYA as a max.

1a. That makes sense. I haven't dropped below 1 FC all summer and rarely do I go below my target of 3 FC.

3. Good to know this is normal.

3a. Will start adding acid at 7.8 from now on - why not.

Thanks again for all your help, Jason. I'm sure I'll be back before the Fall. Take care!

 

[jblizzle]

Now you have me a little concerned.

With a CYA of 30-40ppm, you should never let the FC drop below 2-3ppm. Dropping down to 1ppm is TOO LOW and could have allowed something to start to grow.

Note that with CYA of 50pp, the minimum FC is 4ppm and for 60ppm CYA, the minimum FC is 5ppm.

If you do not have the FAS-DPD chlorine test you will quickly realize you have no way to accurately measure the FC up to the ranges you need ... like dosing up to a target of 7-8ppm to stay above the minimums.

 

[tunacan]

I've been bumping the FC up to 7-8 and by the end of the day it's down to 2-3. There were maybe 3 occasions where I let it go down to 1ppm. I'm hoping that by increasing my CYA I won't be burning through 6ppm's of FC?

And I do have an FAS-DPD, so measuring won't be a problem.

Thanks again!

 

[UnderWaterVanya]

I've been bumping the FC up to 7-8 and by the end of the day it's down to 2-3. There were maybe 3 occasions where I let it go down to 1ppm. I'm hoping that by increasing my CYA I won't be burning through 6ppm's of FC?

And I do have an FAS-DPD, so measuring won't be a problem.

Thanks again!

I'd suspect some Algae... but that's just a guess. I have a 13.5K gallon pool that was sucking 7+ FC a day at 50-60 CYA levels. It seems to have stablized at closer to half that (was 182 oz a day) after shocking and getting the OCLT to drop to 0.5 a day. Not 100% certain - weather has not been the same so it could be me being overly optimistic.

 

[jblizzle]

6ppm of FC per day is pretty high.

I would recommend you do the OCLT before you add more CYA.
Bump the FC up to about 10ppm after dark ... test 1 hour after adding bleach. Leave the pump on all night. Test FC again before the sun comes up. Report the results.
If you pass, the you know the sun is your problem and you can add CYA.
If you fail, you should do the shock process now before raising the CYA as the sun is not your only problem.

 

[tunacan]

oh, that makes sense. Good advice.

I'll try to get that done tonight and will report back in the morning.

Thanks!

 

[tunacan]

Good news I think.


9pm FC: 12

7am FC: 12
CC: 0

8am FC: 12 (after the filter ran for an hour)


I overshot my FC level....the pool calculator called for 264 oz of bleach, and I must have gotten over zealous. Since I passed the OCLT, should I proceed with bumping my CYA to 50-60 and see if I can get my daily FC burn below 6ppm/day? What is an "Acceptable" amount of daily chlorine loss? I'm mostly concerned with reducing my monthly bleach expense and of course transport and storage is a big pain in the behind.

I should mention again that I live 10 miles inland in southern California. My pool receives sun all day every day with an average outdoor temp in the 85-95 range.

Thanks again for all your help!

 

[jblizzle]

Just to confirm the 9PM reading was after the last addition of bleach right? No problem on the overshoot.

Looks like you passed (although usually best to leave the pump running all night). So, you should be good to raise the CYA ... try not to overshoot

If there is such thing as "normal" it would be in the 2-4ppm / day range depending on sun exposure and usage.

If you are tired of lugging the bottles, consider a SWG system.

 

[tunacan]

Thanks for the reply, jblizzle.

Yes, the 9pm reading was done one hour after adding the recommended chlorine required to reach 10ppm (and I hit 12 by accident).

My filter turns on and off a couple of times at night (someone here recommended doing it that way). It runs 6 hours at night and 5 hours during the day.

I actually have to move all of my pool equipment in the near future (my pool needs to be replastered and the deck has to be redone as well). I will probably go for an SWG at that time. My understanding is that they have a pretty hefty upfront cost and then it's fairly cheap on a seasonal basis? If I'm spending $60 a month now, are we talking a 50% savings or more on chlorine?

Thanks again!

 

[jblizzle]

The SWG VERY generally run $500 for a controller and $500 for the cell. The cells last about 3-5 years before needing to be replaced.

If the cell lasts 5 years, the initial cost ends up around $20/month over the 5 years. SWG are not really about saving money (as you will still have to occasionally add bleach and probably more acid to lower to the pH), but more about the convenience of not lugging the bleach everyday and being able to go on vacation and know that FC is still being added to the pool.

 

[calm_like_a_bomb]

Once you install a SWG you should need very little liquid clorine. I replaced my SWG about a month ago, about the same time I found this site. After reading here about Bleach vs. Triclor/pucks/etc I went out and bought 4 gallons of liquid clorine. I've used about a 1/2 gallon, and most of that was right after I bought it and waiting for my SWG to get dialled in. So I'd say your bleach usage would be WAY less than 50%, probably close to only about 10% of what your using now. (if that much)

One thing about the SWGs is they are expensive up front, and expensive to replace. The cells do wear out. I've seen it posted on here that over the live of the SWG its about a wash with buying bleach. Although you don't have to go to the store every week and haul a bunch of bleach to the pool.

CLB