Maxima Clam - To Move or Not To Move



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Mar 2, 2021
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Hi there everybody, long time reefer/r2r lurker, first time poster here. First I want to say what a great resource this community has been for me over the years. Most recently, I'm on the winning side of an 8 month micro algae/Old Tank Syndrome battle in no small thanks to R2R.

So on to my question. As of two weeks ago I am the proud new owner of a ~6-7" Blue Tridacna Maxima. My first clam - "Maximus!" I started off placing him on a flat "rock" I made from reef safe epoxy on the bottom of the tank. He hasn't attached although I've read this can be normal for a larger clam like this. He opens up nicely; doesn't gape, great coloration, no excessive flapping of the mantle, lightning fast reactions to shadow, hasn't tried relocating an iota...nothing to indicate he is unhappy.

However....everything I read about Maxima, especially larger and blue ones, state they need LIGHT. So after week one, I placed him right at about the halfway up point in the rock work. He opened right back up and flow seemed acceptable as the mantle was stable. Two hours later he was flipped upside down on the bottom.

My gut tells me leave him alone. He looks great, why fix what isn't broken and all that. Common wisdom around the web seems to indicate he will die a slow death of starvation if I don't move him up, even though I do supplement phyto and reef roids 1-2 times/week.

Any thoughts/opinions on this? Has anybody successfully kept a large Maxima at the bottom?

Thanks in advance.

Some tank details:
90 Gal. DT with 40 Gal. sump/fuge.
Mostly LPS with some SPS up top.
2 x Kessil A360X using the BRS recommended LPS settings for spectrum/intensity at mid-day (which is 4 hours long).
All major parameters within expected ranges.
Clam distance from light at bottom is ~22 inches, half that where I tried in the rock work. I don't have a PAR meter but guessing I'm at the 100-200 range based on the BRS videos about Kessil.


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Jan 26, 2021
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Is it growing? As with everything in our hobby, if it’s not growing, it’s dying, and if it’s growing, it’s healthy. What PAR is it currently receiving?
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