The single small leather keeps sort of flaking a bit of white away, and folding in. Most of the day only a few polyps come out at random sections on its surface. Rarely will they all come out. The other double leather is growing well (too well!), but throughout the day it changes from being really shrunk down, to brown, orange, black parts/dots on it, and the yellow one is even worse, it rarely extends, and remains shrunk/green for most of the day. The 2 leathers are at opposite ends of the tank.
I've looked into T5s before, and you're right, they start at 24", or 20" at best. My tank is just under 16" wide.
I also have a green brain/maze coral and a pink plate coral, which may need more lighting than I'm giving them, although the brain is halfway up the tank directly under one of the white lights.
I am running carbon in 2 internal filters. It's Seachem Matrix Carbon.
My nitrates are approx 5ppm, and it's PWC
time tomorrow (30%). No phosphate kit, but I feed lightly only once a day usually, and use good quality RO