For water lilies I like to use real soil but most commercial potting mixes contain peat and other things that can turn your water brownish. I find that without a lot of fertalization the commercial 'aquatic' potting mixes that are just crushed terra cotta don't work all that well for lilies although they seem great for marginals. A while back on some web site that sold pond plants I found some potting soil for water lilies and I really liked it, I used it all and wanted to order more but of course now I can't find the site. It was kind of sandy and really dark and didn't color the water at all. I think it was called "just right soil" for Water lilies. Does anybody have a source or even a 'recipe' for a good water lily potting soil? Thanks.