Vitax Stay Wet+ Water Retaining Crystals With Controlled Release fertiliser 200g Retains and releases moisture Feeds for up to four months Ideal for situations susceptible to drought stress. Fast acting water absorbent granules, that can rapidly absorb hundreds of times their own volume of water, acting as a reservoir for plant roots growing in treated media. It can be added to dry compost or pre-wetted as a gel. If pre-hydrating, place the contents of the sachet in a bucket and add 1.5 litres of water before stirring.