My Haddoni disappeared yesterday, what next?

[DasCamel]

So my Haddoni that was hanging out in the back corner of the tank since I believe May, moved and hid during the day. Impressive for his size, but I can't find him. I want to say he's about 14-15 inches across when fully expanded.

At what point do I go looking for him? I would have to move a lot of live rock to do so.

Also, only recent change in the tank has been using a kalkwasser paste to kill off pulsing xenia before it became a bigger issue. My Ph has been higher b/c of it, 8.15 to 8.4 but other parameters were close to normal when I checked yesterday.kH was a little low at 7, CA 420, 0 phosphate/ammonia/ and nitrate. 10% water change day before, RC. Not sure what got him irattated. Everything else looks healthy including my Mag and Crispa. One acro coral has slight browning tips not sure if that's related?

What am I missing?

 

[OrionN]

If you have a deep sand bed, look at your sand bed. Haddoni carpet can withdraw complexly into the sand bed

 

[DasCamel]

Hmmmm.

Hmmmm.

If you have a deep sand bed, look at your sand bed. Haddoni carpet can withdraw complexly into the sand bed

His side of the tank is 4-5 inches deep. I can't tell where he retreated though, either behind or under rock work. Should I give him a few days?

 

[tassod]

They usually come back out the next day or so, they will do this if they feel threatened usually.

 

[Toddrtrex]

An example -- happened within a matter of a second.

This,

to this, (( very close up ))

 

[DasCamel]

Would a large snail do it? Only thing I saw in the area?

Thanks for the pic!

 

[DasCamel]

Just saw him same corner about a 1/3 of the way out. If he inflates fully midday I'll try feeding him.