I have a 2.5G brackish tank with ~40 opae ula and one Amano. Substrate is Tahitian Moon black sand mixed with crushed coral. Everyone seems to be doing well with molting and what not.
I have also had another 2.5G tank set up the same way, but with fresh water. My goal has been to buy more Amanos, convert it to the same salinity, and then spread out the Amanos and opae between the two tanks. Other tanks have demanded more attention, however, and the tank has stayed as-is with a few Endlers and some ramshorn snails.
I have noticed over the past few weeks that the couple of rams that grew up in this tank look amazing. They have large, flawless shells, whereas the snails in my other tanks are smaller and their shells are pitted and marred. I'm guessing this is due to all the calcium in the coral, and that I probably have calcium deficiencies in my other tanks. This is making me think I should add crushed coral to all of my other tanks. I occasionally lose neos to molting issues, and I'm wondering if this would help?
Does anyone have experience good or bad with crushed coral in your neo tanks, and what is the recommended amount per gallon?