I expected after I changed the sand that ta da! Everything would level out.

Since we changed the sand our pool has been very clear (no more green tint), but we have not been able to stabilize the chlorine. I was only adding to 15 ppm at night since our days have been hot and sunny. The first morning after sand we were at 11 ppm FC...the next morning 6 FC...then 8, 9, 9 and then a drop to 5, 4.5 so that I would supplement about a gallon of bleach in the morning. On the first 3 days my CCs were 6, 3 then 11! To conserve chemicals I stopped measuring the CCs every day thinking the point was moot since I was loosing so much FC overnight, but when I did I was getting at least 4ppm. We did have one big thunderstorm over this time period, but days ago and not until after we started seeing some of these levels.

I have been making trips for 12 1.4 bottles of chlorine every other day!

On Wed evening we may have taken an additional step backward. My husband bought clorox with splashgaurd. I added 4.2 gallons to the pool and on Thursday read that the label said it had oxidizer! ...and it did not list any active ingredient including chlorine.

On Thursday 4 adults swam with measurements 2 FC and 4 CC preswim and 1.5 and 4 post swim before adding bleach. The next morning our measurements were 4 ppm FC and 11 ppm CC. We swam Friday afternoon. Friday evening we were at 0.75 and 4 ppm. I added 6.3 gallons of chlorine bleach and an hour later my readings were 7 ppm FC and 12.5 ppm CC.

Is it normal to have such high CCs only an hour after adding the bleach? Is this due to the swimming or the potential addition of oxidizer? ...and what was the stability culprit before we did either of these?

This morning I am at 5.5 ppm FC and still at 12.5 CC the alkalinity is holding at 110 ppm (though the pool store says it is 90) and the pH is between 7.2 and 7.4.

Our new SWG has arrived and I'm tired of adding chlorine (100+ gallons and still counting). Should I wait to install the generator until the pool has "stabilized"? Can high CC damage the generator?

Could you post a full set of water test results? And also describe what the water looks like right now.

Clorox with Splash Gaurd can cause foaming. If you don't get any foaming you should be alright, just avoid adding more.

That is not normal, but if you added non-chlorine shock (potassium monopersulfate aka MPS), then that registers as CC unless you use a special reagent to remove the interference, the Taylor K-2042.