New pool owner - CYA approx 300

[SteffenE]

Temp: 74
FC: 5.4
CC: 0.2
pH: 7.4
TA: 95
CH : 220
CYA: 300 approx
Looks clear, little to no dust on bottom.


First time pool owner, bought the house 2 months ago. Pool has been serviced by same guy for 20+ years he says nobody has been swimming in the pool for the last 10 years. Chlorine has been maintained by solid pucks in a floating device and I'm planning on installing a Pentair IC40 SWG.

Bought a Taylor K2006 test kit and have tested the pool for the last 2 weeks, getting consistent results from both tests. Pool looks clear, little to no dust on the bottom. An overnight FC loss test, showed insignificant (0.4) drop in FC, so no algae growth problems (I guess).

The numbers looks fine, except the CYA number is through the roof. The kit only measures up to 100 but following the extended test kit instructions I've measured it to be approximately 300. I understand CYA should be in the 50-70 range when using a SWG, so I am planning on draining 3/4 of the water.

My question: Am I correct in going down this route? And secondly, how long should I wait after the refill before retesting?


Thanks
Steffen

 

[kimkats]

As soon as the refill is done you can test. There is no need to wait.

You are off to a good start on taking care of your pool with the good test kit.

I am not sure about the 3/4 of the water. Do you know you water table? It might be best to only 1/2 at a time just to be on the safe side. you sure do not want to ruin that beautiful pool!

Kim

 

[rterickson]

Do you know you water table?

With the snowpack at 3% and rainfall below 20% of normal for this time of year in Northern California, I'm guessing it's about a half a mile

 

[JVTrain]

You're probably fine to drain most of the water then. I'd do as much as you can at night or cool, cloudy days (do you have those? ) as I've heard bare plaster exposed to sunlight isn't great for it.

 

[SteffenE]

Thanks for reaffirming me in draining the pool is the right approach. I too have been concerned about ground water pressure. But given that it hasn't rained the last month and that the pool is on a slight slope and totally 60-100 Ft above the valley floor 1/4 mile down the road, I would expect the ground water level to be low.

Thanks
Steffen