As the first company to use hydroponics in pond keeping, we realized that adding dirt to an enclosed ecosystem created multiple problems: dirt can be washed away by pond water or rooted out by Koi; and dirt can introduce “bad” bacteria to your eco-system. We solved most of those with the development of our SPM tm. Additionally, SPM tm leaves lots of surface area for nitrifying bacteria to grow on, especially when seeded with our Bio-Seed tm. SPM tm biodegrades, and when you add our Sludge Away tm Bacteria, there is no mess left on the pond’s bottom.