The goal with the floater is NOT to "do a lot of good" but to "dispose of the tabs safely"! Fill the floater up!

OK. Your pH is high enough to be of some concern. Go to Lowes, and buy a gallon of muriatic acid (saw it for $6.50 today). Find a CLEAN 5 gallon plastic bucket with a handle. Fill it with 2 gallons of WARM water. Add 1/8 - 1/4 gallon of acid. Do this OUTSIDE, with sun or safety glasses AND glove on, AND near a gently running water hose at hand. Watch out for fumes. Once you've added the acid, use the water hose to mix the warm water and acid together, by adding some water directionally, to create a current in the bucket.

Leave the hose running, so if you need to rinse off a spill (on you, or on anything else) you can do so quickly.

Carry the bucket to the pool, and add 1/2 gallon of mix to multiple locations. Wait 2 days. Retest pH; if above 7.8, dose with acid again. Repeat til the pH is below 7.8 OR you are out of acid. Make sure you wait 2 days between doses; without circulation it may take that long to distribute.

Using warm water and highly diluted acid should keep the acid mix from hitting the pool bottom where it could be a problem.

Otherwise, my original list still applies.