Nothing! I've been using polyacrilimide granules for several years with no problems. Dave Anderson > John > > Have you read what happens if the soil gets too dry? > > LB > > > To All, > If you will add some measure of polymer to the potting soil, yes, > even if it is in the garden, rather than in a single pot, your soil will > hold moisture a lot better and will release it to the plant over the time > between waterings. The stuff is available through many garden stores who > use it in hanging pots since they are quite prone to dessication from the > excess breezes that result from hanging in the open air. This polymer is > often available in granules as fine as corn meal, and in larger granules > like rock salt particles. One of the rock salt sized peices will absorb > 400% its volume in water ending up as a blob of jello about 3/8" in > size. the finer grade is often used for bare root planting of tree > seedlings and will make a slimy jello like mixture when fully > saturated. The bare root tree seedlings are literally dipped in this gel > just prior to planting to hold the moisture from soil against the tree's > roots. The gel particles absorb water from the surrounding soil and draws > it to the surface of the roots. with the larger granules, a couple > tablespoons of granules in a 10 qt. pail filled with water will absorb > nearly all of it and tends to hold it better than soil, which can lose it > to drainage and evaporation. The polymer holds onto the water better than > soil particles yet will release it to the plant as needed. The stuff is a > real boon and does not release anything back into the soil yet remains > there waiting to swell back up at the next watering. Great stuff!! > > Cheers, > > John > >