At day 22 the girls are strong enough to have their first bath. The operating theory being: If plant's surfaces are clean and pest free it will enable its leaves to breath and function. The wash I use is NPK Industries MIGHTY WASH. I apply it twice once at day 20 and again 10 days after moving to the flowering tent. The Mighty Wash discourages any parasites or pests which may wander into my indoors system and is nontoxic consisting mainly of water and a few drops of water soluble oils. Two weeks before scheduled harvest when the plants are on 100% water, I use POWER WASH to remove any residues which may be on the plants after the 2nd spraying a few weeks earlier. It is a good general wash to use however, distilled water would work just as well I believe. The power wash is a label of the product by the same company not the process. 
A gentle spraying does not remove any of the good stuff only the undesirable stuff that sticks to the leaves, and flowers which affect the taste of your product.
It is during the final week before harvest when fresh air movement in the tent is important. It is also important to avoid any sudden movement or jarring of the plants. In the process of turning the resin balls at the end of the stalks into maturity, (where they turn opaque) the supporting stalks become brittle and it is easier to dislodge. Harvest handling should be extremely gentle.
A gentle spraying does not remove any of the good stuff only the undesirable stuff that sticks to the leaves, and flowers which affect the taste of your product.
It is during the final week before harvest when fresh air movement in the tent is important. It is also important to avoid any sudden movement or jarring of the plants. In the process of turning the resin balls at the end of the stalks into maturity, (where they turn opaque) the supporting stalks become brittle and it is easier to dislodge. Harvest handling should be extremely gentle.
