Hi Steve;

As Watermom said, 48 ppm at one time is too much for a liner pool . . . but when you've got the green sludge, the total chlorine demand (before you're all cleaned up) can exceed 200ppm! So, by all means, vacuum and clean out all the sludge you can.

Don't add any more CYA, till the sludge and green is gone. Do test CYA as soon as you can -- that will tell you what your normal and maximum chlorine levels need to be.

Do add chlorine in the evening, when it can fight algae without being affected by sunlight.

Do NOT add any 'goop' - floc, clarifier, algaecides, enzymes, phosphate removers, etc.. They will only slow down the process, and in many cases they are NOT compatible with high levels of chlorine, but will INCREASE the amount of chlorine it takes for cleanup.

If your filter needs service or repair, get it done ASAP -- you can't clean up your pool with chemicals alone.

Ben