I have a leather question. I have three leathers in the middle of my 125, all three different types of toadstools. They are all super happy, out all of the time, yet they don't grow. The first one we got as a tiny frag. It has grown to about 3" across then stopped growing, hasn't grown for about 6 months. The others we got a bit bigger and I'm pretty sure the largest one, maybe 8" across, is starting to shrink. All this while they seem to be quite happy. Any ideas? thanks!