i am probably the person who knows the least about lighting so i can't comment on how/what is best, but i keep my GBTA under 250W 14,000K MH bulb and no actinic supplement.
the second pic of the GBTA with bubble is taken with the underwater camera (Olympus 1030W) with under water mode. the first pic of the GBTA is also taken under water BUT with the Sunny day/Beach mode. like i said no actinic supplement, only with 250W 14,000K.