Keeping sand from becoming anaerobic.
I'm planning a tank with only rhizome plants or plants that don't grow in the substrate. I'll be using some type of fine sand (a very thin layer to keep it less likely to develop anaerobic conditions.) How should I keep it clean? Using a gravel vacuum will surely suck up the sand with the water. I can stir parts of it around, but I'd like the sand not to get messed up (not just going to be a flat layer.)
Also, what brand of white sand will be more suitable? Do I need to have larger particles because I won't have any plants planted + I will have a thin layer and a thicker layer towards the back?