OCLT with cover

Yes, it can. I think there are three options here:

1 if you know how much FC your cover consumes subtract it from the number you get in the AM

2 run the OCLT with the cover and if it is less than 1ppm you're good to go, if it is more than 1ppm try it again the next night without the cover

3 run OCLT without the cover

Does your cover touch your pool? If it doesn't then it will not consume chlorine. Those comments are about solar covers that sit on the water and use a little FC.
 
Our cover is a Coverstar autocover with an underguide system. The track is about 2" above the water, and the cover sits down on the surface of the water. So yes, it touches the pool.

I was able to get <1ppm loss overnight with the cover closed. But it seemed like the pool was looking really good for a couple of days before that. So I wondered if the cover may have been contributing to FC loss. In the end, if I extended the SLAM a couple of days, that is not all bad anyway.
 
I have an automatic electric safety cover and it's mostly opaque so if I leave it on all day my chlorine loss is around 0.7 ppm FC over 24 hours at a water temp of around 88ºF. Most of that loss is likely chlorine reacting with the cover. So an OCLT would still be passed if at normal chlorine levels, but at SLAM levels it's dicey. If 0.5 ppm FC over 24 hours were loss from reacting with the cover, then a SLAM has 10 times the active chlorine level so over 8 hours overnight one might have 1.7 ppm FC loss and exceed the OCLT. The fact that you had < 1 ppm FC loss at SLA< levels with the cover on means that your cover isn't consuming very much chlorine.

So generally speaking, I would only do an OCLT at SLAM levels with the cover off.
 
Thread Status
Hello , This thread has been inactive for over 60 days. New postings here are unlikely to be seen or responded to by other members. For better visibility, consider Starting A New Thread.