Water Tests Vary from Pool Stores and Test Kits

by Jamie

I just drained and refilled my pool, and based on your advice purchased a Taylor K2006 test kit. I added only liquid chlorine to shock level, muriatic acid, and sanitizer. I then went to two separate pool stores and had them test my water for a baseline, then used my new Taylor kit for a third evaluation. The results are as follows:

Store 1: FC 2.8 TC 3.3 pH 7.4 Alk 130 CH 250 CYA 30

Store 2: FC 5.09 TC 5.3 pH 7.6 Alk 128 CH 200 CYA 42

Taylor FC 7.0 TC 0.4 pH 7.4 Alk 160 CH 130 CYA 40

All three tests vary so widely, I have no confidence in any of the actual levels tested. Both pool stores use the automatic spin disks and accompanying software to print out the results. Both stores have sold me chemicals that didn't solve my previous cloudy water problem, leading me to drain the pool and refill. The pool is beautiful now, but I have serious concerns about proper maintenance in the future if I cannot trust available water analysis. Can you please advise me on this?

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Hello Jamie. Welcome to the world of going of the pool store and having them test your water. I was clearing up a pool for a friend and took a sample to two different stores. One had a CYA of 80ppm and the other had 20ppm. The first I would need to a 2/3 drain and refill and the 2nd reading recommended more CYA. My Taylor kit said the CYA was 40ppm which is in range of 30 - 50ppm. My recommendation would be to get very comfortable with your kit and don't rely on the pool store. Be sure the Reagents are fresh and watch my videos on how to

use it. I trained lifeguards at the Y (16 year old kids) on how to use the kit and they did it.

Your readings are good. A few little adjustments and the water will be clear once again. First is to be sure the filter is perfectly working. I don't have the kind of filter so I can only use this general statement. Next is to decrease the pH to 7.0 with acid. Use 12 oz. per 10k gallons to reduce 0.2. Once that's finished it's time to vacuum the bottom then backwash. And last is to add enough liquid chlorine to bring the FC up to 12 - 14ppm. Use 1 gallon per 10k gallons to accomplish this. If you have a 24k gallon pool then use 3 gallons. So here's the process:

PM
Filter (filtration system) working
Reduce the pH to 7.0 - 7.2
Vacuum then backwash/clean filter (cartridge)
Add 1 gallon of chlorine per 10k gallons of pool water

AM
Same process

PM
Same process

Keep doing this (AM and PM) until the water is clear and you don't lose more more than 2ppm FC between applications. This will kill all of the algae/bacteria in the pool and is the way to clear up and balance pool water.

If you feel your situation is more complex than this, I do phone and/or SKYPE consultations. It makes things go much faster and many people have found it extremely beneficial, saving them time and money in the long run. All your questions will be answered. I have nothing to sell you so you know I'm not bias. If you purchase a personal phone consult you'll get all 3 eBooks for free.

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Robert