Quote Originally Posted by leejp
(OTO... is this a FC or TC measurement?) and 3 PPM is the max the kit'll measure (recommended is 1.0~1.5) Does Ben's kit measure beyond 3 PPMs?

I do have to say I'm a bit nervous... I've had iron staining problems and with high FC, I'm afraid that the iron will be forced out of the water onto the liner. Man I have to get that iron out of the pool!
OTO measues total chlorine. Some people say that if you read the test withing 15 seconds you can get a free chlorine reading and then let it sit for about 2 minutes to get your total chlorine reading but it is a rough guide at best. If the color gets darker upon standing you most likely have combined chlorine but I would not trust it to tell you the amount.
Ben's kit has both OTO and FAS-DPD titration tests. The OTO test is good for a quick check on your levels(and Ben's wil measure to 5 ppm I believe) which in theory should be done daily and the FAS-DPD test will be able to test levels up to, I believe 50 ppm free and combined chlorine with an accuracy of either .2 or .5 ppm and would be your weekly test or your test when there are problems.
Bad news about the iron, unless your pool water is replaced or you filter all the pool water with an iron removing resin it will stay in your pool. When conditions are right(wrong?) it will deposit in your pool as a stain. When you put in a metal treatment it will dissolve back into the water. Nothing wrong with adding metal treatment when needed. If you are very lucky , when it deposits out of the water it will do it in your filter medium and not in the pool and it can then be removed by changing the filter medium. Works out well if you use DE, pretty costly if you use a cartridge.