Okay, I'm done tinkering this evening. I took a bunch of pictures, but haven't got them assembled on a webpage yet.
To answer some of your questions, I bought
Helios T5-11 Deluxe Actinic Blue. Model #: HO T5-II 54AB-R 54w 47" Item #23589
The UVb 11,000k Is on the list, but that isn't what I got. Heck, I might like that better, now that I saw your list and the description on the box. These are what is listed on the packaging:
Daylight
Pink - Plant Grow
Actiinic Blue
Actinic Combo
UVb 6,700k Reptile
UVb 11,000k Marine
Because of the width of my canopy with the additional wood I added last year to raise it up 6" higher than it was before, the new bulbs couldn't be put lower down as I'd planned. Still they are now about 3" lower than my VHO bulbs, which I've left in place, unplugged. Btw, each light fixture has its own cord, and it states to
not plug them into an extension cord so I'll need to get a multiprong plug for my timer. The cords are 2 prong, not three (grounded).
My tank is a standard 55g, so that would be 18" tall. Taking account for the DSB, there is 14" of water to penetrate, and the bulbs are 9" off the water. Because of the aluminum reflectors, these bulbs won't get cooked by my 175w MH bulbs. Those bulbs are old 10,000K Ushios that badly need replacing. My guess is once I get those new bulbs in, my tank will look great. Currently, the 10,000K bulbs running by themselves make the tank very yellow. Bleeech.
This evening, I built a dangling platform to hold my clam safely, because I know my tank still has whelks and I don't want them to get a shot at eating my new acquisition. It is supported from an acrylic frame that spans the top of the tank. The platform is about 3"x3" and 2" tall, filled with 1" of Live Sand. It hangs mid tank, in an area that won't shade any light loving corals, and it is inaccessible to any snails or whelks. My plan is to take a shot glass, invert it in the tank and fill it up with phyto, and lower it over the clam to give it time to eat each day. Hopefully that will be as easy to do as it was to type.
The clam has been opening nicely, and according to my ruler is is 1.25" in length. Pictures will be posted soon.