I think part of my problem is I have the wrong substrate? It is just normal sand. I'm moving house in a year, so I didn't want to fork out for aqua soil, if it will all turn to mud in a year when I move it. My tank is 100gals, so that's hundreds of pounds worth of AS. My problem is, when I trim my stem plants, I find it really hard to anchor them back in the sand. They keep floating up. It's alright with plants that have lots of roots, but while the stem plants have a little bit of root once I've trimmed the bottoms off, it's not enough to anchor them in my sand. My biggest problem is with my nessea crassicaulis, which is thriving and growing REALLY fast! So as soon as it grows enough root to anchor itself, it's time for a re-trim and it starts all over again. Is the problem my substrate, or is there a method everyone else uses that I don't know about?