CYA Rising, PH Falling

I switched over from Baquacil to Chlorine this year and it has been fantastic! Your site has been a great help. I am confused about a few things though. My PH hovers around 7.4. I can add borax and bring it up but it goes back to 7.4 in a couple of days. Also, my CYA has started to climb from 50 to 75. I have been using Tri-Chl tablets in a floater for my normal chlorine and Cal Hypo for shock. My calcium hardness is at 270, my TA seems to stay around 150 and my free chlorine level stays at 5. My pool temperature has been ranging from 84 to 88 degrees. My pool is approximately 13,000 gallon inground.

I keep reading to use bleach to prevent the CYA from rising. I assume the only way to add this is in the liquid bleach form. Do you just add a certain amount per day. With the Tri Chl, I keep around three 3 " tablets in the floater at all times but have no idea what the proper procedure is for bleach. What about Cal Hypo, is that a better alternative?

Hello and welcome! Your pH is fine at 7.4, so don't fight it. 7.4 is a great pH reading. Your CYA is climbing because trichlor is stabilized which means it has CYA in it. You need to STOP using trichlor. CYA at 75 is already high and you don't want it any higher. Also, do not use any dichlor shock powder because it is also stabilized. (Also, trichlor is acidic which is also why your pH is falling.)

Is this a vinyl or gunite pool? Vinyl pools need no calcium. Gunite pools need calcium between 200-400. I would just use bleach instead of cal-hypo. High calcium along with high TA can cause cloudy water issues.

Remove the floaters and just use bleach. Take a look at the Best Guess table in my signature below. With a CYA of 75, you need to be keeping your chlorine between 5-10ppm ALL the time. If it dips below 5, you risk an algae bloom. Test your chlorine every evening and add enough bleach to get the cl level back to 10ppm. In a 13K pool, each quart of 6% bleach will add about 1.2ppm of chlorine. Use that as a reference to help you decide how much bleach to add each evening. With a CYA of 75, you may find that you only need to add bleach every couple of evenings.

You'll need a good test kit if you don't already have one. The one we recommend is the Taylor K-2006 or 2006C (same kit, larger bottle of some reagents). If you buy it through the Amazon link in my signature, the Pool Forum makes a little money on the sale which helps us keep this form online. Only buy if the seller is Amato Industries, however. Some other sellers are substituting the K-2005 which you do NOT want.

Come back if you have more questions! Welcome to the Pool Forum! By the way --- you did the right thing converting to chlorine and getting rid of the Baquagoop! Smart decision!

EDIT -- You may want to lower your alk a little. Directions can be found here:

http://www.poolsolutions.com/gd/lowe...p-by-step.html

The pool is a vinyl pool and I use a Taylor K-2006C test kit for checking everything. Is there any alternatives to bleach that does not drive the TA and CYA up. My Calcium hardness should drop at some point. Any added water from my well has almost a 0 in calcium hardness (it dropped last year and the "pool store" got me to increase it (wish I had read this site beforehand), they also got me to increase my TA (wish I had read this site beforehand).....got to love Pool Stores!

You can use cal-hypo for awhile but when it starts getting high, you may have cloudy water. Calcium hardness does not go away or drop on its own. The only way to remove it is to do a partial drain and refill.

You may be able to find some liquid pool store chlorine that is the same thing as bleach (sodium hypochlorite) but just a higher concentration than household bleach which is 6%.

Do you not want to use bleach?

It just seems that bleach could gt expensive if it has to be added at 1 to 2 qts. a day, maybe not. What do you do to drop the CYA, just use bleach and over time it drops or is there so other additive that should be used to lower the CYA?

Actually, bleach is one of the cheaper sources of chlorine.

The only way to lower CYA is to do a partial drain and refill. You NEVER want to totally drain a pool, however. Since you fill from a well which can cause a whole host of other problems, I think if it were me, I'd just live with the CYA of 75 and run higher chlorine numbers to compensate for it. Like I said above, with a higher CYA like you have, you may find that you only have to add bleach every 2 or 3 days so it may not be as expensive as you suspect.

Thanks so much, you have been a great help Watermom!!!

You are very welcome. That is why we are here! :)

Just a little follow-up. As you told me, I switched to bleach. My PH is still at 7.4, my has dropped to TA=100, my CYA is now 70, my CH has dropped and is now at 150 and it is taking me around one to 1.5 qts of bleach per evening to maintain my free clorine at 5 to 6. I AM GETTING THERE!!