Depends on size
Babies that start off 1/2” to 1” I put on a plug. When they get larger then the plug i put the plug on a eco rock frag mount
In pic below the white stone under the plate is the plug. The dome rock under is the eco rock plug mount.
Plates have a under skeleton that grows along the surface it rests on. It doesn’t actually encrust. It’s more like…non adhesive encrusting.
If you put them on something flat, lkke sand bed, they will grow as a flat plate which is typical. And fine, until the day you have a paramater out of whack, or a crab/shrimp/fish bites or, or a who knows what event, that causes the coral to retract in. And then sand gets in the skeletal ridges. And then when the coral opens again it either gets scraped by the fine sharp sand grains, or, it senses the sand grains and opens up everywhere except that spot. Regardless. That spot then becomes a hazard and often goes unnoticed or mistreated. It’s an open door into the coral for bacteria and infections. And this simple explanation is why I believe many many people lose plate corals
Ok. I rambled. <stay on target. Stay on target>
With the method below, you will have a plate that grows to be volcano shaped! I don’t know if anyone has seen volcano shaped plates before and wonder how it’s done, well, this is how. It will overgrow the plug, and then grow down along the eco rock and form a mound shape plate. In my experience it will take approx 1.5-2 years depending on starting size. So the eco rock will hold you over for a while.
Once it over grows the eco rock, I would suggest mounting to a frag mount tile. 3x3. 4x4. I’ve seen circular ones. Some people use Home Depot ceramic tile but I am unsure what type to recommend that’s reef safe. Can do your own research there. Bottom of eco rock is flat and smooth. Perfect for some gorilla glue gel to attach to the next mount device. From that time onwards the plate will level out and grow flat.
Here is a pic of one farther along
The plate was put on a plug, just like the earlier example, but I had not found the eco rock product yet. So the plug was put in my frag rack. It overgrew the plug, very nicely I must say, and now is at the frag rack level. It will now taper off and grow flat. Unless, I elevate it further. I need to assess this guy to see if an eco rock is an option or if it’s too late.
Now, I’d you already have a flat plate that is larger than a plug, and in need of secure mounting, I would advise to get it on a tile and then just put the tile in the sand and check daily to make sure the tile isn’t getting submerged in the sand. The flat smooth tile is a safe surface for the plate to grow along and much safer than being in the sand. I would attach with a SOLID ring made from a long noodle of reef putty. You don’t want critters and pests getting under your plate coral and boring holes in it.
Think of a pool float
You want to make this shape from reef putty and put on the underside of the plate, then smush that onto the tile so there are no gaps or pathways under the plate. It can dry and solidify under water. A few days later check that it dried and didn’t contract and make holes. These can be filled with more epoxy or gel super glue. Your plate will now be secure.
Oh yea smush it down on the tile so the plate is maybe 1/4-1/2 inch above the tile. We don’t need it 1” up in the air. We want it to look natural and the closer the tile the better. In a few weeks / months the new growth will extend to the tile and cover the gap. Smaller the gap the faster it’s hidden
If anything doesn’t make sense let me know!