CYA test says zero, but should I add more?

[Newdude]

It always rounds to the next 10 so it’s an 71-79 =80. It’s been rumored a lot lately that folks have seen it burn off more in the peak season after 88 degrees. Hopefully between that, and some well timed rain you’ll be fine

If the power goes out for a couple days, I'm buying a pallet of chlorine.

Ha !! But no. You aren’t adding the full 10ppm (?) each day, just what you lose (2-4). It does burn off a little quicker at higher FCs but not enough to need a pallet.

 

[EnoughToBeDangerous]

Yes but if the power is out and I come back in 3 days and the pool is green or cloudy, I need to boost the fc to 26 to clear it. We'll see how it goes. If there is a problem I guess I can also do a partial drain and refill, it's not that easy with my setup so hopefully rain and vacuuming/ backwashing will do it.

 

[EnoughToBeDangerous]

So the CYA level made it's way down to the 50 over the summer, probably rain and backwashing did it. I would say that with the CYA up at 80, it was not great for me. TFP recommends keeping the CYA at 70 or above for a SWG pool, but it does not recommend slamming at 70.

So what do you do if the pool is a little cloudy? In a trouble free pool, you would SLAM. But I'd have to drain about 20% of my water to get to a CYA level recommended for slamming, or try to slam at 28+ FC. With the pool at 50 CYA, I guess I'm using my SWG cell up quicker, but with the oversized cell I got after reading TFP, it doesn't seem like a huge problem.

 

[Newdude]

So when folks come in with sky high CYA, We say to drain to make the SLAM target lower *and* be better off going forward. For SWG folks who need to be 70+ after the fact, we say to let it ride and SLaM with the higher target.

I guess I'm using my SWG cell up quicker, but with the oversized cell I got after reading TFP, it doesn't seem like a huge problem

You will use exactly whatever ‘extra’ run hours you use. Say, you normally run 12 hours and switch to 24/7 hours for the SLAM. It’s 84 hours per week off the life of the 10k hour (?) unit. You will NEVER know it died 84 hours early when the time comes. You could do it 10 times and still be hard pressed to see an 800 hour difference 10 weeks ‘early’……. 5-7 years later.

So yes, it ‘uses lifespan’ but IMHO the details are rarely explained in a way that don’t seem scary.

Now. There are those who want to squeeze every minute of life out of their unit. If it helps them sleep better then by ALL means I wish them well in their mission.

*disclaimer. While the SWG can certainly help, it shoots itself in the foot in the process. For many swamp SLAMs it simply cant come close to producing enough FC (or producing it quick enough). So we say to shut it off. As the pool clears and it’s a filtering fight instead, it most certainly will help but has to be off overnight to be able to Overnight Chlorine Loss Test to pass the SLAM. So to only use it a little and only at certain times kinda makes it moot altogether so we usually just recommend to go with liquid and follow the well established path.