don't let it bother you if you use a turkey baster blow off your rocks every other day
the cayno will decrease over time as Coraline forms underneath it and with a good clean up crew your cayno will disappear
this is cayno I've had red , green , yellowish brown on the rock to the left of my flowerpot as the cayno dies off Coraline will form looking like this second pict
once the cayno settles and coraline forms the rock really shows there colors ,