Is this the norm? (Salt water)

[SteveTech]

I have finally seem to have found the balance of the SWCG for my pool, which is around 47% running at low speed for 16 hours a day.. I get right around 6.9-7.0 TC and the same with FC. PH is a "every three day" test and add due to salt water.. I have two questions around CYA and CH

CYA - over a 2.5 to 3 week time frame, drops from about 70 or so down to about 55-57, Is that normal?

CH - the "Store" says 150-400 is the norm and I am currently sitting at 256, but the app says that I should be around 450? I ask as I go to the store about once a month outside of my testing.. says I need to add 22lbs of CC

Appreciated

 

[ajw22]

CYA - over a 2.5 to 3 week time frame, drops from about 70 or so down to about 55-57, Is that normal?

CYA degades as the water temperature increases. At 90F you can lose 10ppm or more of CYA per month. Warmer will lose more.

CH - the "Store" says 150-400 is the norm and I am currently sitting at 256, but the app says that I should be around 450? I ask as I go to the store about once a month outside of my testing.. says I need to add 22lbs of CC

What test kit are you using?

250 is ok. 350 may be better for colder water temps in the winter.

What is the CH of your fill water?

 

[mmcwhorter]

CH: I'm at 250 right now and I agree, that's OK. I usually kick it up to 350 ppm for the winter cover/storage as mentioned herein. In part, I'll SLAM my pool before closing using 73% Cal-Hypo (well dissolved in a 5-gallon bucket). That brings CH up a tiny bit. And then add the regular calcium chloride later. As to CYA....and I know this might be frowned upon: I have about 40 leftover/inherited 3-inch stabilzed tabs and when CYA needs a little pump upward, I'll throw 2 tabs in a floater and keep it up till I get back to a more desirable level....were only talking from 50-60 ppm or thereabouts. Pool math says one pound of trichlor will add 3 ppm CYA to my pool volume.

 

[Newdude]

CYA....and I know this might be frowned upon: I have about 40 leftover/inherited 3-inch stabilzed tabs and when CYA needs a little pump upward, I'll throw 2 tabs in a floater and keep it up till I get back to a more desirable level....were only talking from 50-60 ppm or thereabouts. Pool math says one pound of trichlor will add 3 ppm CYA to my pool volume.

No no no. We frown upon blind use. You know *exactly* what you are adding and what it will do. And why. Bravo.

Also, I wanted to point out that while you're nice and dialed in at the moment, daily UV demand will decrease slowly per day as the days get shorter and the sun angle lowers. So you'll need to be on the lookout for when these settings make too much FC per day, then turn it down a skootch. In the spring it's the exact opposite, needing a little more every couple of weeks. Basically, it's

Open
Up
Up
Up
Up
Down
Down
Down
Close.

 

[mmcwhorter]

In fact, my observations agree with the Up Up Up Down Down Down you mention... because recently I switched from 60% to 40% CL generation amount on my IC-40. FC was running around 11. While it's free, it's a bit high...Now I'm down in the 5-7 range. I'll do a Boost every so often and all is well.

 

[SteveTech]

CYA degades as the water temperature increases. At 90F you can lose 10ppm or more of CYA per month. Warmer will lose more.

Yep, water has been in the 88-91 deg range for a number of weeks, so makes sense..

I'm going to need to pick up some CC to get the 256 up to 300 or so.. but otherwise the pool sparkles