High Phosphates

[Watermom]

With a CYA of 60, you have to keep your chlorine between 5-10ppm ALL the time or you get algae. That's what is happening in your pool. To get rid of it, you need to shock the pool up to 20ppm and keep the chlorine at that high level until you can go from sundown one evening until within two hours the next morning without losing more than 1ppm of chlorine overnight. We then usually suggest keeping the chlorine high for one additional day and then letting it drift down.

In a 20K gallon pool, each gallon (4 quarts) of 6% bleach will add 3ppm if chlorine. Use that as a reference to help you figure out doses of bleach to add. Each time you test, add enough bleach to get back to 20. The more consistently you can keep it there, the faster it will clear up. Un

Until you get the K-2006, you can force your kit to read higher with dilution. Not super accurate, but better than nothing.

Info here: Testing Without a Good Kit

Don't add anything else right now but bleach. If your pH goes to 8 or higher, you'll want to use some muriatic acid to lower it. But, before doing so, please read the link in Jan's sig above about using it safely.

Hope this helps!

[NelliNell]

One more question before I add the bleach. Should I add it immediately this morning or wait until late today? The pool store always told me it was best to add it when the sun is going down or not as strong and your post references sundown but wasn't sure if I just need to get something in now since I have no chlorine reading?

Thanks for your help!
Jeff

[aylad]

With a zero chlorine, you need to get bleach in it today--NOW!

If the water is green, go ahead and shock the pool per Watermom's instructions. You'll need to test as often as you can during the day, and add whatever amount of bleach you need to get back up to the shock level. The more consistent you are about keeping it at that high level, the quicker the pool will clear.

The reference to sundown that Watermom made was for testing, after the pool has cleared, to make sure all the algae is gone. If you test one night and again the next morning without having added any more chlorine to the pool, and don't lose any in that time, then you're finished shocking and can let the chlorine drift back down. But while you still have green water, you just need to test as often as possible and focus on maintaining that shock level of 20 ppm.

Janet

[NelliNell]

That's the thing, the water is crystal clear

[Watermom]

It may be clear now, but if you let your chlorine drop to 0 with a CYA reading of 60, then you probably have something starting in there that hasn't "bloomed" yet. My advice is the same. Go ahead and shock the pool. It may be that doing so one time will be all that you need and you'll find that you don't lose more than 1ppm of chlorine overnight. If that is the case, then you'll be good to go as long as you don't let the chlorine drop again. But, my opinion is that it is better to go ahead and shock a pool that looks clear rather than chance it and end up with a green pool.

[NelliNell]

Can I assume it isn't safe to go in the pool until I'm done with this process and am able to let the chlorine drop to normal levels?

[aylad]

I wouldn't have a problem with going in the pool, but you don't want to wear brand new suits while the pool is at shock level. As long as the water is clear and there is "some" chlorine in the pool, I wouldn't have a problem swimming in it.