hi every one well been away again and on return i inspected my tank nothink much different i thought checked the watere all was fine then thought would clean the glass when the light came on just finished cleaning when all i can explain it as is a puff of sand (or ground up stone) came from a hole in a rock then about a minute later another puff from another hole all told have found 3 hole didnt see any thing else for the rest of the evening will wait till the light go out tonight to see if any think else pops out how ever looking around the net i recon it might be a peanut worm any thought anyone