I'm continuing to post updates on my other thread but I have a quick question.

We are getting close to finishing the shock process. When I get home from work, I plan to test FC and add any needed chlorine. How long do I need to wait before re-testing FC for purposes of the OCLT test? Pool School says at least 30 minutes. Is anything longer than that and dark out OK?

Once we pass the test, do we then allow FC to dissapate until it nears our target of 7 for CYA of 60 before running a new full set of tests?

I usually wait an hour, it depends how much circulation you have. Having it be dark when you are testing is optimal since there is no UV on the water to reduce FC. Also, make sure you test in the morning before the sun hits the pool.

Make sure you pass all three "done shocking" criteria (see my sig), but then allow FC to drop to 5-9 level (used poolcalculator, do not let it drop below 5 if you can help it). Then you should start regular daily and weekly testing...not sure of what you meant by "running a new full set of tests".

Good luck on the OCLT!

Thanks. I'm running a fairly high FC rate due to the CYA of 70. By new full set of tests I guess I meant pH, TA, etc. We've only been checking FC since starting the shocking. We went with limited pump use for about a week and in FL that's not good. When we received our test kit, pH was pretty high and we used the pool calculator to add MA. We never checked pH after that to confirm because we immediately started the shocking process.

ph should be the only test affected by high FC. Above 10 ppm FC, pH testing typically reads higher than it would be once FC is below 10 ppm. However, there is no harm in waiting to test the rest until the FC has dropped.