Which Portion Of Gravel Has The Most Bacteria?

[Miss Wiggle]

i find for vaccing fine sand just hover the vac a couple of cm's above the substrate and move it im small circles, the movement of the water lifts the poop up off the sand and then it's close enough to the vac to be sucked up........ takes a few go's to get the knack of it but that's what works best for me.