When are rock lifts necessary? I just read a little bit about them in another post and was curious about them. What can be used as a rock lift? Does the whole rock's weight need to be dispersed? If you have any information at all, can you please post!

I've read a few threads 1st, but still unsure. Rock is "holding" for existing established tank. I just bought about 20# of totoka fresh in that day or day b4. It has good coraline, pink, orange and green, a little plant life, and some black junk, but not the soft black sponge that easily...