Oh, you posted pics of multicolored small (?) gravel. I didn't see anything like sand...but either kind, it's a matter of cleanliness more than sharpness. Even with plants you can vacuum down a bit, say 1/4 inch (or cm if that's your preferred measurement).
Pygmy corys are not totally bottom fish. They like to swim in the water column often. Just something to consider.
You need to practice vacuuming w/small substrate. It takes a while to be able to do it well. Short, quick shallow down & up movements works for me. If you do suck up some substrate you can rinse it & return it to your tank. You can do it if I can!
Pygmy corys are not totally bottom fish. They like to swim in the water column often. Just something to consider.
You need to practice vacuuming w/small substrate. It takes a while to be able to do it well. Short, quick shallow down & up movements works for me. If you do suck up some substrate you can rinse it & return it to your tank. You can do it if I can!