Its always good to find another authoritative web site for pool maintenance! I've been through the pool store jungle of mystery potions which don't seem to do much except drain my wallet. Now I use my local dealer for cyanuric acid, a gel block for the skimmer to clear the water (it does work, but sloooowly) and tests to compare with my own results.

I've been using the bleach shock method with good results. I do find that the OTO chlorine test using a crude titration method doesn't let me directly read the high levels for effective shocking. To compensate I've diluted the pool sample with an equal amount of distilled water, and then doubled the indicated level after adding the prescribed 5 drops. Is this a reasonably accurate method? The strips are hopeless for this....