I did have them covered completely but just a day or so before this I took them out and dropped them in acid:water 1:3 for about 1/2 hour, toothbrushed them, then put in a bucket of water and ran for an hour. I did a couple 620's I have back in the sump too. I hate corraline now. I just picked up a handled scraper Tues night so it seems easier to clean than the credit card way. I've been kalking the mouths of some shrooms lately and then they shrink and I can pick them off with my finger sometimes. I don't mind the green striped ones they seem to stay down in the lower left but those regular green like to spread around.