Is it safe to swim?

[TrampledUF]

I saw green in the pool a couple days ago, so I shocked to kill it, and crossed my fingers that by today the Cl would be low enough to swim for people coming over.

CYA was 60, so PoolMath said SLAM level is 24. I skimped a little and added CalHypo such that it would get to 20.

Now I'm testing Cl and the kit is telling me maybe somewhere between 15 and 20. It's hard to tell, because even when I add only 1 drop of reagent, it turns an orange color instead of yellow. So it looks between 3 and 5, so 4 times 5 (because only 1 drop), that makes 20. PoolMath says that with CYA 60, I want Free Cl to be 5 - 9.

In reality, the CYA is probably a little higher than 60, because I've had pucks in since the CYA test.

So if CYA is 65 and Free Chlorine is 15 - 20, is it safe to swim if we don't put our heads in???

 

[mknauss]

You can safely swim in a pool as long as the FC is above the minimum and at or below SLAM level based on your CYA. You must also be able to see the bottom of the pool in the deep end of the pool.

You did not SLAM the pool water. If you had algae, you still need to. Or you will be constantly fighting it.

Your CYA is 70, you cannot measure a CYA of 65. Round up. The vial is logarithmic.

 

[mknauss]

I do not understand what kind of test you are using for chlorine? Do you have a proper test kit?

 

[Donldson]

The way you are trying to use the OTO test is completely wrong. It does not matter how many drops you add, that only changes the strength of the color. It doesn't extrapolate the way you think it does.

Since you cannot accurately measure your chlorine level except to say that it is high you cannot accurately say that your water is safe or not. So no, I would absolutely not suggest allowing people to swim.

 

[TrampledUF]

I said CYA=65 b/c I had the pool store do a test a week ago, and they reported 60, but there have been pucks in since then, so I estimated 65.

I do have the TFP test kit, I just forgot that it has a method to test Cl levels above 5. I'm going to do that now.

 

[mknauss]

Do the CYA test too. If you are basing things on a pool store test, realize they get that test wrong nearly all the time.