Pollen can still be viable a couple of weeks after release.
A mellow solution of bleach/water will sterilize. (2 tsp:gallon, I believe)
Spray all non-living things in growroom, and wipe down. Lamp and hood should be cool and unplugged before spraying...cleaned and dried before use.

About hydro...not a technique I use, nor one that I care to use.

Don't bleach the soil.