Hi Jilted,

The very first thing you need to do is have them get that pH up above 7.0. Start with about 1/4 box of Borax, poured very slowly into the skimmer, breaking up clumps as you go. Give it a couple of hours to circulate, and then retest pH. If pH isn't above 7.0, then add another 1/4 box. Keep this up until you have it between 7.0-7.8. Be careful to pour it very slowly so it won't clump up in the pipes.

Second...each gallon of 6% bleach is only going to raise the chlorine by 1.7 ppm, and with CYA at 0, the chlorine needs to be raised to 12-15 ppm and held there until the water clears up. So with the chlorine at 0, which I expect you to find today since the water is green and there's no CYA, the initial dose should be 7 gallons. They'll have to hold the chlorine there by adding bleach as many times a day as possible--but to know how much bleach to add, they're going to have to test the water to see what's been eaten up. They need to get a good test kit, or at a very minimum an OTO and keep the chlorine in the "orange" range. Of course, this is going to need to be done with the pump/filter running, preferably 24/7 until the water clears up.

I wouldn't start with the CYA yet until the water is cleared up. If they used tablets all last year, I expect that they closed with a high CYA, and since there's none now, there's gonna be a huge chlorine demand while the chlorine eats up the ammonia left when the CYA degraded. It's gonna take a lot of bleach to fix, but it can be done--and it needs to be, if they want to not have problems all summer.

Is the water light green and clear, or is there obvious algae growing on the walls? What is the chemical name of the granules (dichlor, cal-hypo, etc). Also, do you know what the CYA level was when they closed last year? Do you know if they have metals in the water? Have you checked the ingredients on the bucket of tabs to see if there is copper listed?