If you can vaccum to waste, then that's an option for removal of what's on the bottom, though obviously you have to do so carefully so as not to stir it up. If it is just to easy to stir up, then adding a flocculant (OMNI Liquid Floc Plus) would help consolidate the particles so they don't stir up as much and you'd have to vacuum to waste to remove them.
If that doesn't work or is not an option for you, you can intentionally stir it up, then add a clarifier and run the pump 24/7 to try and catch this stuff in the filter, that you then need to clean or backwash. If you don't have a floor drain (and you may not since it's above ground), then getting this stuff to the filter via the skimmer will be time-consuming.
I wouldn't worry about TDS. TDS is mostly salt from chlorine usage. In a residential pool, the amount of extra organics is very small and unlikely to cause turbidity problems (and if they did, then a floc or clarifier will consolidate such particles). And in your case, you've got actual precipitate you can see (i.e. it's not dissolved).
Finally, please get a full set of water chemistry numbers including Free Chlorine (FC), Combined Chlorine (CC) or Total Chlorine (TC), pH, Total Alkalinity (TA), Cyanuric Acid (CYA) and Calcium Hardness (CH). If the pool is over-saturated with calcium carbonate, then that could be this powder, though usually it precipitates more as scale than powder and the water would remain cloudy. If it turns out that the powder is just from over-saturation, then there are several options depending on your water parameters.