So I've had this T. Maxima for a bit over a year now, maybe 14 months, and it seems to be doing fine until very recently. Over the last week or so it's developed ... splotches... they're a very pale green. you could call them white (in contrast to the mantle) but they don't look white to me, and they're not visually the same as in another recent thread (see: http://www.3reef.com/forums/clams/white-spot-clams-mantel-121725.html) but I'm concerned all the same. Basic tank params are in line for a reef.... Ca 450-480 ºDKH 7.5 - 8 pH 8.02-8.1 ºF 78-80 All nitrogen compounds are below normal detectable limits for general hobbyist water test kits (I use API) Lighting is 2x 150W 15,000ºK AquaMaxx HQI about 10" above water surface. The clam is on a shell half on the bottom of the tank... 58gal AGA. Last replaced 4/18/11. About a month ago I lost power on my AC unit and the tank spiked to 88ºF for about 12 hours. Everything got mad at me, but only lost one coral (moseleya sp.). I tested and ºDKH came back at about 2, double and triple checked, and it was still very low. Nothing else was out of whack. Raised it back up over the course of a few days to 8, and it's held steady since. I noticed the spots about a day after feeding Alagen's "Phyco Pure Reef Blend" phytoplankton. I bought it as a hold over for my normal feeding of DT's (about once a month on average) since the LFS can't seem to get a hold of DTs right now... When I fed this time my clam really seemed to notice. Usually I let the DTs fall down on it from a baster for a few minutes and it doesn't react in any obvious way. With the Phyco Pure it instantly closed as soon as the phyto touched it's mantle. Anyways, my initial concern is that the Phyco Pure has had some kind of reaction. Also, I'm generally concerned that the Phyco Pure is coincidental to a more general decline in my clams health. If anyone can help me on this I'd really appreciate it. I'm reading up on clams again, and not really finding any examples of this kind of discoloration. Lots of general bleaching info, but nothing that visually identifies with what I am seeing. Basically I guess my question is: Can any ID this phenomenon? Is it bleaching or something else? picture: You can see the splotches on the lower right side of the mantle on 2 sections, and on the upper right side on one section.