waterdrop
Enthusiastic "Re-Beginner"
Gosh, I wish I knew that answer better myself! I can tell you that for what you're asking, gravel cleaning under plants, I mentally divide plants into two groups -- the amazon swords and crypts and other plants that come with a nice crown and a bunch of roots are ones that my understanding is that they should not have their roots disturbed too much and the plant should not be "moved." By contrast, the "stem" plants, which I think of as those that come "snipped off" and not having any or many roots when you get them, can be pulled out and replanted without a bad reaction. A third group, the ones like java ferns and mosses and things that are supposed to be attached to driftwood and rocks and things above the sustrate are of course the easiest to move around sometimes. So I have -some- plants that I move around and gravel siphon underneath, but quite a few others that I don not disturb. In some patches of plants what I do is gently put my cylinder down into the thick bunch of plants and then give it a tight "vibration" motion to stir up as much debris that's hiding in there as possible -- this sometimes seems to get me more debris than my cleaning of the pure gravel areas does!
It brings up a different and interesting question of what it is that causes some plants to lose all their leaves but then be able to re-generate them. When I first got my crypt (wendtii "brown" I believe) it lost all leaves to the crown but I left it in there and its come back with many leaves. I do not know whether in general this is thought to be because of the moving (the disturbing of the roots therefor) or because the plant has experienced a water chemistry change and/or a change in carbon level perhaps.
~~waterdrop~~
