Your sig says Taylor 2000 is that K-2006 or K-2005? Different kits.
"The rain makes it green" - This is proof that you shouldn't listen to the poolstore guy. About anything. Rain makes pools green only because pool owners stop adding chlorine when it rains.
I wouldn't worry about TDS.

Given the fact that the pool was recently green, I think you should:
Bring the FC above the minimum shock level (I think 15 for this pool) on Ben's Best Guess Chart and don't let it drop below. Test and add bleach / LC to restore shock level at least twice a day.
Run the filter 24/7 - cleaning as needed (when sand filter pressure rises 6-10 psi).
Brush the walls and floor of the pool daily.
Continue this regimen until one day after:
The pool loses less that 1 ppm FC between sunset and sunrise
And there is nearly zero CC (less than one drop)
And the pool is clear.
Wear old suits to swim while following this shock procedure - they may be damaged.