I have a 55 gal and some pesty green hair alge. I know that a sea hare can rid a tank of alge in no time but are they worth it?They had a few at the pet shop and they were about 4". I was told that they hide under the sand by day and come out at night. They dug one up for me to see and it was quite unsightly. Do I realy want one? Anyone out there have or had one?