Clams under PC's... this BEGS for opinionated answers.
Yes Clams work under PC's. There is more to the environment than light.
I have kept Maxima's and Derasa's under PCS. Admitedly these are the "easier" clams to keep. But mine have had growth rates that took me by suprise.
Here is my opinionated answer.
Clams require light, water movement, Water Volume, consistent water perams, nutrients, and a stable place to grow.
Lights. Under PC's my clams are centered under the lights. I choose small clams with VERY large mantles... no sickies for me. I feed them while they are small with various concoctions. They are not completely photosynthetic for a while (can't remember the approx size). So... I choose a clam with a larger mantle knowing that it has a greater surface area to gather light and is probably healthier than it's anemic neighbors.
Water Movement. The Ocean doesn't sit still. Neither should your tank. Lots of pumps, lots of timers. If you've snorkled, dove, or just swam in the ocean where our critters come from you see how turbulent it really is.
Water Volume: I know it has worked in Nano's... but i'd keep Clams in larger tanks. Temperature, params, everything is more stable as you go larger. Heatwaves don't effect as much, neither do cold waves, water-changes, fish/invert deaths, etc. etc. To those that keep Nano's... great job... you guys do what I won't attempt. I'd rather balance a beem that is 10' long than 10". It moves slower.
Consistent water parameters. The ocean is fairly stable (at least away from shore). My Tank (200 gal) has settled into a consistency that I can't break if I tried. 8.1 Ph, 10 (on german scale) Carb Hard., 80 degrees, 450 calcium, 0 trates/trites/phosphates. People fight what their ecosystem wants to stabalize at... they have PH swings, temp swings, calcium swings... this will doom anything sensative. Create consistent maintenance habits and your tank will be as stable as ever.
Nutrients... see above. Add Calcium to the list of things Clams need.
Stability. When the ocean picks up and rearranges the seafloor... it's usually a title wave. Not Good. I placed my maxima in a spot that was supposed to be overnight... so I could secure him the way I wanted in my monti the next day... by morning he was cemented in place and I have never moved him again. Instead I'll frag my monti and move it to my clam. If you can't move Mohammad to the mountain...
Lastly... just try it. I kept a flowerpot for 5 years before I started listening to the experts... once I took expert advice... my flowerpot crashed and died.
I kept hard corals, soft corals, fish, everything under waaaaay too little light for 3-4 years. Now all those corals that are pushing 10 years old that are supposed to be "intense light only" corals bleach when I pull them out of the caves and corners they live (and multiply) in.
It goes back to stability. Once you properly aclimate anything to your tank environment... don't change that environment. A dirty tank will work forever with most things as long as it is always dirty.... a very bright tank will work with most things as long as it is always bright. A dim works wonders as long as it is always dim.
Sorry for the verbose response... have at it and enjoy the experiment.
