method of testing chlorine levels

[Whidster]

I am having trouble reading the yellow block for the chlorine test. :?: My subjective reading is higher than the reading I get when I test 10ml of water with the powder/drops method.

For example tonight I think the yellow was at about 3.5 or so whereas the powder/drop test came up with 2.5.

I am opting for testing with the powder and 0871 drops. What are your thoughts on this?

 

[JasonLion]

The OTO chlorine test (drops turn the sample some shade of yellow) is best for doing a simple chlorine/no chlorine check. One typical approach is to use the OTO test 6 days a week just to make sure nothing has gone really wrong and then use the full FAS-DPD test once a week to recalibrate how much chlorine you are adding each day.

 

[Whidster]

Thanks Jason. I add some chlorine every nite (we haven't installed the SW yet). So is a guesstimate acceptable 6 days a week using the OTO, then do the FAS/DPD on day 7?

I think I am paranoid of getting watermold again like we did with the Baquacil if we we off at all.

 

[JasonLion]

Yes, at least once you are familiar with the pool going six days on guesstimates based on approx OTO readings is just fine. The only tricky part is to get a good base estimate to work from, which often takes a couple of weeks of testing with FAS-DPD to develop. But once you have things on track all you really need to watch for is something going wildly wrong, which OTO can tell you.