- Jun 22, 2014
- 52,078
- Pool Size
- 17888
- Surface
- Fiberglass
- Chlorine
- Salt Water Generator
- SWG Type
- CircuPool RJ-45 Plus
That's usually from one of two things:But does anyone want to take an educated guess on why the pool looks so good but won’t hold chlorine ?
1 - Either there is excessive organic material in the water (like algae); it can be transparent so you may not see it.
2 - CYA is too low (below 30) and the sun's UV is grabbing all the free chlorine.
Below is my own cheat-cheat I like to pass along to help with the CYA test.
CYA Testing:
Proper lighting is critical for the CYA test, so you want to test for CYA outside on a bright sunny day. Use the mixing bottle to gently mix the required amounts of pool water and R-0013 reagent, let sit for 30 seconds, then gently mix again. Recommend standing outside with your back to the sun and the view tube in the shade of your body at waist level. Then, begin squirting the mixed solution into the skinny tube. Watch the black dot until it completely disappears. Once it disappears, record the CYA reading. To help the eyes and prevent staring at the dot, some people find it better to pour & view in stages. Pour some solution into the viewing tube, look away, then look back again for the dot. Repeat as necessary until you feel the dot is gone. After the first CYA test, you can pour the mixed solution from the skinny view tube back to the mixing bottle, gently shake, and do the same test a second, third, or fourth time to instill consistency in your technique, become more comfortable with the testing, and validate your own CYA reading. Finally, if you still doubt your own reading, have a friend do the test with you and compare results.
To be sure you have no algae (in ANY form), we perform the Overnight Chlorine Loss Test. This is very helpful to do before increasing the CYA level. So if there is ANY doubt about algae, especially if you just opened from winter, it's best to do an Overnight Chlorine Loss Test. It's just a matter of taking two accurate FC tests with your K-2006C kit. One test before bed and one early the next morning before the sun hits the water.