Plate coral placement?

No i totally get what you mean, when I bought the coral it wasnt extended at all and I don't think the LFS owner knew how to care for it cause he told me to put a small rock under it

 

Nope, you usually want these guys on the sand, with plenty of room around them. They'll move themselves, by inflating and deflating parts of their bodies, so you want plenty of time to be able to keep them from getting to sting your other corals.

You want to keep excessive amounts of sand off of them, but they'll shed sand themselves, so a bit isn't harmful. They even dig themselves out of 6+ inches of sand if they get buried in storms in the wild, so a couple grains won't kill them.

Mine has a good amount of flow now, but used to be just as poofy under near zero flow. I think they're relatively tolerant of flow. They really do need a bit of light to survive, more than you'd think, but sandbed works for them. They're very good at catching lots of small particulates with their mucous layer, so the lower than natural light levels shouldn't hurt them.

My clowns host in my plate, and I don't think the plate minds. They're not super aggressive about getting all up in his business, though, so that may be why they're not having a noticeable impact on its inflation.

 

yeah..i look at it as.
1. params in check
2. enough lighting
3. other corals doing fine

then the rock has to be making it uncomfortable..i had my torch one time a little to close to the rocks and when it got really long it would brush it and finally closed that head up for a few days until i moved it a little farther from the rocks

 

i have kept a long tentacle plate coral on the sand for 5 or 6 months. They have a very sensitive underside that can be cut be ANY rocks. This includes crushed coral as substrate. i have seen people keep them on their rockwork only to have them mysteriously take a turn for the worse. i believe this to be caused by damage to the soft tissue underneath.
Also, do you spot feed? They are a photosynthetic coral, however mine likes to be spot fed a couple times a week. I feed mine chunks of squid or shell fish.
I hope your coral does well and i hope this has been of some help.

 

he looks much better now that I put him on the sandbed, I do spot feed twice a week with PE mysis, thanks for all the help

 

In nature, plate corals are often found on rocks, but there is a lot of variation among plate corals. I'm sure not all will do well on rocks and especially in a confined aquarium, they may be more susceptible to damage.

 

Yea I have never been able to figure that one out. Placement in the wild for some fungia is indeed on rock, but there are several different kinds of fungia. Perhaps the ones most commonly available in the trade are not the exact same ones that live and reproduce on rocks. Ones I have seen in the wild look like little mushroom (hence the name fungia) with stocks elevating the primary base off the rocks.

When in doubt, or you see a decline, placement in the sand bed seems like an easy intervention.