I have one that is around 12" across now, was around 4 inches when I got him. Thanks size and equipment is below on my hobby exp line. Mine has settled where to Closed Loop heads converge about 16" from the surface wedged in a crack.
Water params are:
PH 8.1 to 8.3
Temp 78
Calc 420
A, trite and trate 0
Alk 12.3 dKh
Phos - 0
Water turn over is 8x via overflow via sump and return pump
Closed loop via 3000 GPH Sequnce pump
so total is aorund 18X turn over
Lighting is 3x 150W MH, 4x 96 Duals
Light cycle is Duals 12 hrs, MH 8hr
Feeding - Mysis twice a week, silversides 3 times a week
Good luck
Ron