T5 lighting & purples acro keeping

[spawn]

Here are some pics of the suspects
This 1 I got about a month ago from a friend who has High No3 but had 1 250w 14k Halide over it, it was way darker

The 2 right in front of the Monti, 1 is a purple milli, the other a purple Acro w/Green polyps, both used to be much darker/richer purple

& finally this 1 was darker & richer as well.

I just switched lights about 4 months ago to a tek 6 bulb fixture & now I'm thinking of going to a T5 halide combo. I'd prefer to stay as is but wonder if it's possible to influence the pigment with just T5 & some kind of supplement, food or mineral?
Also I just got this deep water frag from another canreefer last night & would like to keep it's color. It's color is a bit darker than the others but gives you an idea of where they started. Purple is really the only color I'm having an issue keeping. It's the 1 to the lower left.