I would immediately add 5 cups of bleach to your water--regular ordinary bleach (6% concentration) to get your chlorine level at least to a fighting chance of stopping the algae that's growing. Check your water 3x a day with whatever you have, tho the 6-way HTH kit from Walmart is the second best kit you can get. You'll want to keep your chlorine level between 10 and 15 for now, till the slime is gone, and till we get a full set of test numbers.

I'm guessing the actual water level is 24", not 30" which puts your pool at 1700 gallons. One quart of bleach will add 8.8 ppm (parts per million) of chlorine to it. Forget the powder for now.

Carl