Proper lighting for small to mid-size clams?

[Rpmgreen88]

Pardon the unfamiliarity, my grandma gifted me some smallish (2-3 inch) pismo clams that she had bred in her tank, in hopes that I could raise a few of them on my own. She recommended quite a bit of heavy duty lighting equipment, but I'm tight on money and was wondering if there is a way I can do right by these clams with what I have available. I read online that some strong LEDs will work in place of halidaes, and I have a quite strong Ott lamp that I figure will do the job, but my questions are
1. Will this light even work as food for their symbiotic algea bits?
And
2. I read some folks online "feed" their clams with light for 12 hours at a time, but I also read that clams need a slow adjusting period to light. Is it dangerous to go from bright light to near complete darkness in between these 12 hour cycles?

(I'm not trying to eat these guys, just wanted to raise some little friends)

 

[vetteguy53081]

Clams need Goid lighting and moderate water flow
Ph not to exceed 8.3
Salinity not to exceed 1.026
Alk not to exceed 9
Ca not to exceed 440
Nitrate not to exceed.6
Temperature not to exceed 80