I have a relatively new tank set-up. I would also like to know the differences between certain Z's & P's. My tank has been up about 3 mos. I started stocking it after about 6 weeks. So far I have stocked 25 different Z's & P's. Not large colonies, usually only around 5 polyps, sometimes I get a bone and recieve 8-10 polyps. I wanted to set this tank up with only frags, no colonies. Of the 25, I have lost around 6. They just never did well. I even tried relocating them, which most of the time, ends up making matters worse. I like to get them, let them set for a couple days then put them somewhere permanent around the lower 1/3 of my rockwork. I am letting one Paly, just grow in the sand. One of my hermit crabs tore it apart. There are now 3 different pcs. I seem to have better luck with Z's than P's ??? I am wanting to save my sand bed mostly for Acans, but am thinking of just trying to find more Z's & P's to also put down there. I'd like to cover up my sandbed to increase my flow up top. I have all SPS up there with LPS in the middle. Not very good with names, plus I am color-blind. Most of what I order, looks different than what it looked like when ordered. So I just try to order what I like, that looks different. I have also found that it's not that easy to remove them from plugs. they do better when left on. Now most of my colonies are anywhere from 10-20 polyps. The ones that have survived initial acclimation and liked thier original placement are doing great. Some are already nearly as large as dimes. The first thing that I noticed, getting back into the hobby after being out for several years, was the smaller size of all of the polyps... I have one Paly that I fragged. I took it from the plug and glued it onto a chunk of LR in three places. It has done well. Started with 5 polyps, now have 9 polyps with around 4-5 more babies not yet fully formed. I feel that they do multiply quicker if split up. But on this frag, I experimented. I stuck 1/2 of the rock in the shade of my cave. The polyps in the shade have only added one more, but they have increased in size and the bases or tubes have extended. These polyps are 2-3 times the size of thier well lit brothers. They are about 1/2" from the rock, where the others are still hugging tight to the rock. I'm going to try to situate the rock at a happy medium to see what happens then.