CYA/Chlorine Questions?

[mkfmedic]

Hi Folks,
We had our first "large" party with a number of kids and adults swimming in our small pool. It was a great time! After being away at work for two days, I came home to test the water and found that we have very low chlorine. No problem, adjust the Jandy SWG system and wait. I tested the water again last night, and the chlorine still remains very low, between 1 - 2.

Before the overfilling and party, I was maintaining 3 - 5 ppm for chlorine at 40% on the Jandy SWG System. After the party, I kicked it up to 60% anticipating the need to add some chlorine to the pool. After finding low numbers, I then adjusted to 100%, followed by the last test.

I have a Taylor Kit, but only strips to test CYA. The strips indicate that the CYA is very low. It was my understanding that once CYA is in the water it stays in the water? Could the heavy use combined with the accidental overfilling of my pool cause the CYA to drop from the "Normal" to "Low" range on the strips? By the way, I ordered the Pool Solutions Testing Kit and am anxiously awaiting its arrival!

Here is my Pool/Equipment
Approximately 11,000 - 12,000 gallons.
Jandy 1400 SWG wtih DelOzone System.
DE60 Filter
Navigator Suction Cleaner

Test Results
TC - Maybe 1
FC - Maybe 1
CC - 0

PH - 8.2 approximately, still having trouble matching the colors (my vision)
Alk - 100 approximatley.

Is there a way to test specifically for CYA? Is there a CYA calculator out there on the site? I'm at work again today (I work 48 hour shifts), and will be home tomorrow. My plan is to buy some CYA, and add slowly to adjust. I will also be adding some muriatic acid to lower my PH number. I was also thinking since I am running so low on chlorine that rather than turning up the SWG, just adding some bleach to "kick start" the chlorine.

Any suggestions or thoughts. They are greatly appreciated!

Thanks in advance,

Mike

[Phillbo]

Get a sample tested at a pool store to make sure your CYA is low before adding more. Buy one of Ben's kits and you can test it yourself in the future. Not sure how much you over filled but if you lost/replaced a lot of water, you could have dropped the CYA a little.

Your high Ph could aslo cause the chlorine to be low. Add acid to get that down and see if it helps as well.

You may want to consider using a little bleach to get your numbers up insted of cranking the SWG up to max. That will shorten the cell life.

[mas985]

A few things may be at work here. First, if water is replaced in the pool as in an overflow situation, the CYA will drop which could reduce the chlorine generation of the cell. Second, high PH will also reduce the chlorine generated by the cell. Third, scale on the cell will also reduce generation. You did not post CH so I can't tell if this is a problem or not.

I would first inspect the cell for any scale and clean it too. Next, I would drop the PH and see if that doesn't fix your problem. If you still are low in chlorine, then you may need to increase the CYA.

Also, you can get a separate CYA drop kit for a more accurate measurement.

[Rangeball]

If you have a Walmart nearby and if they have the 5 or 6 way drop test kit, it tests for CYA if you want to avoid the pool store.

[mkfmedic]

Thanks to everyone for your replies.

A couple of things. Great idea on getting the water tested. I don't want to rely on a "strip" test to assess the amount of CYA in the water. I have ordered one of Ben's Test Kits and am anxiously awaiting its shipment/arrival.

I've only been at this for a month, the pool has been filled for just over a month, but would my calcium build up already be a problem? As I mentioned, I was only having to run the SWG at 35 - 40% to maintain my chlorine. It is only in the past couple of days that I have noticed the drop in chlorine and increase in PH. I assumed, maybe incorrectly, that the accidental overflow and resulting refill caused these issues.

Finally, I learned from this site that I can use bleach to suppliment my chlorine when necessary. Great advice and I will use it to help raise my numbers if it turns out to be necessary. I have a Leslies near my home and will have them test my water for CYA. I will also add acid to lower my PH and will continue from there.

Thanks Again, I truly appreciate the advice!

Mike

[Looony2nz]

Mike -
I know you from the other board - on Gardenweb......
I'll bet you anything its the fact that your PH is too high. Our SWG did the same thing....stopped producing chlorine due to the PH being too high., so now we make sure we keep our PH in check.
You need acid to bring your PH down.......most positively your answer.

Let us know if that worked.
Shari

[mkfmedic]

Hi Shari,

I knew I recognized the screen name. Thanks for the advice. As it turns out, after adding muriatic acid, my PH is down and my chlorine has soared due to the 100% setting on the SWCG. So, taking your advice, I will not ad CYA yet, it appears I don't need it with the Chlorine levels I am currently showing. I turned the SWCG down to 50% to see how the chlorine levels hold, and with the addition of the acid, it appears that the Ph/chlorine/cya situation may be resolved.

I will be leaving for work tomorrow for the next two to three days, and the real test will be my results when I return on Tuesday morning. I think with everyone's advice I am certainly heading in the right direction. There is something very satisfying about taking care of your own pool, I think I am really going to enjoy the little challenges from time to time! Having a great resource to refer to makes the process that much easier!

Thanks again and it is great to "read" a familiar face.

Mike

[Looony2nz]

hi, and hey, no problem. Ya still need "some" CYA. Ours has been kinda low to ok for a few weeks and the chlorine level is holding. It took us a couple weeks to find the "right" percentage (what seems to be good) on the SWG. I think we're at 68% with "low" (60-80???) CYA. For a while there, the chlorine was 5 each time we tested., finally, I think its down to 3-4 since we kept inching the SWG percentage down very slightly.
yes, there is something satisfying about maintaining the pool yourself, especially when I've heard from neighbors etc. about how their pool guy comes and goes and "doesn't do much".
Anyway, good luck !
Make sure you post pics when your new addition arrives

Regards,
Shari