Hello. I have a rock which apparently my nerite snail has not discovered... The rock has been in there for about 3 months, when the tank was still in the brown diatom algae stages, and my nerite snail handled it beautifully... Except in one area: that rock. There is still diatom algae there, and I would like her to eat it. I didn't mind that much until a beautiful thick carpet of green algae formed on the rock where there were no diatoms, and I had this vision of the entire rock having this. How would I entice her to eat what is there now so that more green algae (which she strangely will not eat) will be able to take hold? Thanks.