Quote Originally Posted by CarlD View Post
I'm no SWG expert but after reading hundreds of posts it is clear that SWGs require higher-than-normal CYA levels--80ppm being about the recommended level. If you have the SWG's manual, read it--it should tell you.
Depending on the manufacturer it is usually anywhere between 50-100 ppm with 60-80 being the most common. In actual practice 80 ppm works out well unless there is a lot of sun in such places as Florida, Arizona, California, etc. Then bumping it to 100 has been found beneficial.
If your pool is uncovered, that would explain the rise in pH--you've somehow been aerating it and that raises pH.
SWGs areate the water by producing hydrogen gas at one of the electrodes when they are generating. This causes CO2 to outgas and the pH to rise. This is why running a very low TA helps with pH stability.
A CC of .5 may actually be only .2--did you re-do the test using 25ml of water instead of 10ml? In that case, each drop of the re-agent only represents .2ppm, not .5ppm. Clearly, .2 is STILL only an indication of the maximum the CC can be.

You MAY want to briefly raise your SWG level to kill any CC you have--0 is the best number. Or you can shock the pool with bleach or liquid chlorine.
Not needed, Just turn the unit on and the CC should be gone in abourt 48 hours.
Also, you should also find that with your SWG you can keep your FC at a lower level than the "Best Guess" table indicates--because the chlorine levels are far most constant, plus the salinity is a growth inhibiter for algae.
With a CYA of 100 keep the FC at about 5 ppm.
I hope this helps a little.
Hope this clears some things up.