I did some agua scaping over the weekend and noticed a considerable amount of empty hermit crab/snail shells. The number of my clean up crew is also diminshed not suprisingly. I counted 15 snails and 8 hermits. Tank is very clean,65 gallon,tek- light with 6x39 watt bulbs and sump. Should I increase my cleanup crew or do you think this is just the result of the crew versus the dirt naturally balancing out? About six months ago I noticed when I fed the tank all the cleanup crew went nuts chasing the food like they were starving.