FishyBen

Why are you interested in gravel vacuuming? Is it for aesthetic purposes, tank cleanliness, perhaps water quality. If you have no ammonia or nitrite then all gravel vacing is doing is removing shrimp and loach food. If you really want to gravel vac I have found that slightly wiggling the vac tube above the gravel without actually touching the gravel creates enough water agitation to remove the top layer of filth. This can leave all the great alive stuff in the substrate intact.