RiverbendPoolSupply.com - Todd's Blog - Episode 75

Rain, rain is here to stay. Coming back every single day.
The foreseeable future has nothing but rain for our May day's. Keep a watchful eye on your chlorine levels and perhaps add a few extra ounces of PolyQuat60 for good measure. When we have heavy consecutive rainy days your chlorine and other algae defenses can rapidly deplete. Add an extra chlorine tablet, a couple extra ounces of PolyQuat60 and keep an eye on your filter pressure.
DE Filter back washing should be done AT LEAST ONCE per month! Atleast! That's a bare minimum. You should also backwash if your filter pressure rises by 10 PSI. Cartridge filters should be cleaned every 3 months OR when the pressure jumps 10 PSI. Two weeks ago I cleaned out the filter for our fountain. This past Saturday the rain dumped a whole ton of pollen in the fountain which caused the filter to clog, so I cleaned it again.
There is no set in stone answer to when you should clean your filter. Filter cleanings are dependent upon many factors.
Despite all the rain we have been having my pool looks great. No algae or cloudiness.
Free Chlorine - .6 PPM
Total Chlorine - .6 PPM
This is enough for now. I added one tablet this week, but I may go back and add a second one just for good measure since we are about to have another 10 straight rainy days.
PH - 7.4
Perfect for Saturation Index, Bather Comfort, and Chlorine Function (chlorine is 60% HOCL - the killing form - when PH is 7.4). Because of the buffering power of Borate I have not had to add acid to this pool in months now.
Total Alkalinity - 40 PPM
This is too low. With my other chemical balances (PH, Calcium, Temperature and TDS) the Saturation Index is lower than -.3 which means the pool water is prone to be corrosive and aggressive. I added a 5 pound bucket of alkalinty up to bring the TA up. I want the Saturation Index to be between -.3 and .3 as this is considered balanced water.
Calcium Hardness - 225 PPM
With all the rain we have had the calcium may have diluted from 275 to 225. We will see what happens between now and next week.
Cyanuric Acid - 15 PPM
This is enough to protect the low level of chlorine that we are holding. a 15 PPM level of cyanuric acid will protect up to 1.5 ppm Free Chlorine from UV destruction. Since I am using less than 1 PPM FC I do not need more cyanuric acid.
Phosphates - 100 PPB
My CV-700 has caught up to the phosphate levels and they are back down to 100 PPB. I will soon have them maintained at 0 PPB.
Borate - 80 PPM.
Perfect. At this level Borate is a powerful PH buffer, algaecide, scale inhibitor and water clarifier.
Next week we will see what the Total Alkalinity is back up to and continue monitoring the Saturation Index and Hardness levels.