CYA levels and titrating chlorine with low salt generator and autocover

[Bob2010]

Hello everyone, new pool owner hoping for some advice. The pool was finished end of last swim season so was not really used. Basically took some time to try to balance the water chemistry ( though used store testing at that time) and then closed it up for the year.

Thankfully this year it opened up fairly clear and I did the SLAM process which I have just finished. ( clear water, OCLT 0-0.5 X2, and CC 0) Testing results of water as follows: TFpro salt with magnetic stir. ( ph, TA pre SLAM)
CYA 30-35 (did the test twice but still a bit new at interpreting)
CH 150
Ph 7.3
TA 120
Salt 1800 ( 1200-1800 for SWG)
FC 13.

I have a couple of questions in relation to what I should do now with my SWG given my circumstances. SWG remains off and has been this entire time. For context the pool is in an area where it is exposed to sun from 9 am-7pm roughly. However due to the kids and safety concerns the pool is covered with our auto cover when not in use. For uncovered sun exposure, we use the pool usually 3x from M-F from around 4pm-7pm and maybe one day on the weekend from 12pm-5pm. The rest is night swimming after sunset. Pool is covered at all other times.

I am trying to figure out how to dial in my SWG given this. The other complicating factor is it is the low salt system Aquarite which I am not able to find a lot of clear information on. I'm not sure the output but based on a previous thread I read, amps *0.18 when active would lead me to believe it's in the ball park of 0.7lbs per day. I have a VS speed pump which runs pretty much 24 hours a day and due to short plumbing runs and low electricity rates I plan to continue that so there is only really one variable to adjust for the SWG which is % output. The current VS timers will activate the SWG 100% of the time from what I had set up last year.

Overall I have two questions.

1) Given the above setup how would you dial in the SWG, where should I start, how often should I test etc. In addition to that, should I bump it up when the pool is open to the sun, or for the period after it is open to the sun?

2) What should I do with my CYA levels? the manufacturer manual states to run CYA at "20-30 ppm ( if necessary )". From what I have read, more than this seems to be better. However, I'm not sure if higher CYA levels will cause any issue with this low salt system. Also considering the pool is covered the majority of the time, should I still run my CYA higher as well? I have no issue running it higher if it is still likely to be beneficial and also would not interfere with the equipment and SWG in anyway. I suspect not but really am not able to find much information.

Thanks in advance!

 

[PoolStored]

1) Given the above setup how would you dial in the SWG, where should I start, how often should I test etc. In addition to that, should I bump it up when the pool is open to the sun, or for the period after it is open to the sun?

I know my FC demand by month. I run it 15%, for example in the month of June. When I open for a couple hours and I swim, I bump to 40%. When we open for the day with lots of swimmers, I bump to 50-60%. I turn back to 15% at the end of the night. You can figure out daily demand using starting FC + FC added with SWCG - Ending FC...when the cover is on, no usage. Same when you use the pool. After a while, you will learn what it need. Best to bump it before usage, not after.

2) What should I do with my CYA levels? the manufacturer manual states to run CYA at "20-30 ppm ( if necessary )". From what I have read, more than this seems to be better. However, I'm not sure if higher CYA levels will cause any issue with this low salt system. Also considering the pool is covered the majority of the time, should I still run my CYA higher as well? I have no issue running it higher if it is still likely to be beneficial and also would not interfere with the equipment and SWG in anyway. I suspect not but really am not able to find much information.

Higher CYA will not cause any issues with low salt systems, other than it will require less output (extending cell life). Even when covered, you will need less FC at higher CYA. I would recommend you try 60ppm CYA. For Ontario, should be ok. I'm in Ohio and keep my CYA at 70. My daily FC demand with cover is 2.0. When we have sun and a few swimmers FC demand is about 4.0. The worst I have seen is 5.5FC demand with lots of swimmers. 60 is a good compromise...If you were in Arizona, I'd recommend 80!

Try 60 and always follow this for your FC levels. Link-->FC/CYA Levels

 

[PoolStored]

BTW, always round your CYA up to the next value ending in 0. Or, fill to each line and read at the line. Your CYA is 40.

 

[wireform]

I would recommend set it and forget kind of but not completely. I wouldn't go below 60 for the cya and I'd aim for a hot 9-10 for the fc.Check daily for the next 2 weeks to see that it remains at that magic number meaning you'd tweek the output to end up at an FC of 9. You also need to check it around the same time of the day to see a trend. I wouldn't go the "raise and lower" way because the day there's more sun exposure it'll drop more then the other days but it'll catch up. Running it hot will keep you safe even on the days with more exposure as you won't dip into the danger zone with the FC.