I am new to this forum. As a physician-scientist I feel it is imperative to try to understand biological mechanisms and relationships as much as humanly possible. I recently purchased a home with an in-ground pool. The stats re the pool are shown in my signature. As an aside I had a formal pool inspection that indicated high cyanuric acid levels but the inspector did not specifically indicate that this would mandate dumping pool water and replacing with water without CA. The house has a low producing well and city water is not cheap → $400 per 10,000 gallons. I was instructed to completely empty the pool by one pool service person only to learn that that could result in the pool heaving itself out of the ground depending on the height of the water table. Another pool service charging an average of $70-93 per visit said they normally do not test for CH, TA, or CA, even after I explained my current pool chem results. Now the "Great CA Debate".
I spent hours reading various forum discussions (here and elsewhere) on CA. One company manufacturing a chlorinated granular product sold at Costco told me that their product contained no CA (Kem-Tek ALL in ONE), which I later learned was false. All Dichlor and Trichlor has CA in it. Only liquid chlorine or Calcium Hypochlorite products have no CA. Given the issue of water shortage, high cost of water, the pain in the butt to drain part of your pool (in my case half =8,000 gallons), I wondered why pool owners were not told to switch to the non-CA products or even to a liquid chlorine dispenser like the Stenner pump that sense the chlorine level and appropriately delivers the amount of chlorine needed (I would like to start a new thread just on the Stenner pumps).
but now I have come across two papers that state that CA is not an issue at all and that pool drainage is not needed as long as FC levels are 1 ppm to kill bacteria or 3 ppm to kill algae. Clearly I would want both under control so my goal would be 3 ppm. I am giving those that read this thread the URL to the PDF on the paper by Kuechler from 2004 on the Great CA Debate. Here it is
Another paper is attached to this email on "debunking the chlorine lock myth. Oops. The forum has a max file size of 19 KB. So here is the shortened URL:
There are readable by anyone. The bottom line:
[B][B]"cyanuric acid levels in excess of 200 ppm had no impact whatsoever on a pool's sanitation provided that the chlorine residual was maintained between 2 and 3 ppm."
The pool water has & remains crystal clear since before I owned the house (during inspection & escrow period) and from Nov to this moment, despite CA levels exceeding 300 ppm and with a 1:4 dilution the CA is 88, which would equate with 352 ppm (explaining why the reading is high when CA is undiluted.
Another issue is measuring TA when CA is high. I have read that one should correct for this by dividing CA by 3 and subtracting that amount from TA. My TA without correction is 208 using LaMotte ColorQ. CA as above divided by 3 = 117. That would mean my corrected TA is 208-117 or 91, which is said to be within the normal range.
Therefore, TWO main issues in this post: 1) the real significance of CA vs bactericidal and algicidal effects and making adjustments on pool chemistry pending other values.