I couldn't find any real particulars on it during a quick search, but IMO
there's other alternatives that are a far better choice, designed for aquarium use. Also, I wouldn't agree sand is easier to clean than gravel as it's much lighter and if using a python system you have a better chance at sucking it all up whereas the gravel is heavier and will fall back down. Devils advocate, sand will keep detritus to the top layer whereas gravel it falls in the nooks and crannies. Just my thoughts.