> If you drain half and refill with fresh water, your CYA level should drop by half.

Thank you. That is the only thing that made any sense to me.

> The 2006 has .75 oz bottles and the 2006C has 2 oz. bottles which makes it a better price per ounce.

That makes the decision easy. If I am going to be testing daily then I am much better off with the larger bottles. Thank you again.

By the way, we keep our pool covered most of the day. That provides us with 2 benefits - the pool stays cleaner because leaves and other garbage is not falling into it and the water stays nice and warm and we can (probably) use it longer during the year since the water will still be warm enough to use in early Spring and late Fall. However I don't know how covering the pool affects the water chemistry. I assume that the chlorine in the water will degrade more slowly when the pool is covered because there is no sunlight to destroy it, but I don't know how the added temperature from the sun's warming the water in an "enclosed" space will affect what is happening chemically in the pool.

By "covered" I mean we have a pliable plastic cover that we drag over the pool after we are in it and remove before we enter it. Since the pool is so small (roughly circular with a diameter of about 10 feet) pulling it on and off is very simple and quick.

Will the chlorine levels drop more quickly if the pool is covered than if it is left uncovered? Or more slowly? Will not having direct sunlight on the pool surface affect the pH of the water? Or not? Will I need to watch and test more often or less often when the pool is covered?