I have a 10 gallon that is so densely planted that I have not done a water change/vacuuming in almost a year (Filtered with an AC50 with sponge, Purigen, and pot scrubbers). I never vacuum, though I probably should. I don't because there's no way for me to without disturbing plants. I'll occasionally stir up the water a bit to get some of the gunk circulating through the filter, but thats about it. It's stocked with, besides plants, 3 Khuli Loaches, ~10 nerite snails, 2 apple snails (or whatever the "Mystery Snails" at pet stores are), a male betta, a female betta, a young senegal bichir, 5 or 6 Ottos and 8 zebra danios. All that and I don't do water changes, just top off evaporated. Anytime I do a WC, It seems like I've thrown everything out of whack because I'll get 2 weeks of algae and bacteria blooms. So I just leave it be.
just note that this didnt happen until the tank was well established. I use Fluorite for the substrate. I think ocassional light vacuuming could be helpful to start, keeping algae down and good water, but if you get to the point where you can't see the back of the tank through the jungle, you can probably ease off
edit: oh and I dose with Prime daily, and have a DIY CO2 pumping in through a micro diffuser.
