As I said on Matt's thread, I'm becoming obsessed with getting the environment exactly right for these finicky sticks. Its becoming a mental illness of sorts:bounce3:
So in the interest of attempting to pass along some useful information, here is what I think I learned:
I started with 6 blue bulbs, two super actinics, and 4 purple bulbs. When mixed together this is actually not all that much red light, its much more blue than anything. Corals were doing okay under this mix but not growing as fast as I had seen in the past.
I swapped photoperiods. Blasting the corals with blue light for an extended amount of time each day seemed to result in growth, but I lost some of the contrasting colors that make Acroporas so amazing. I was hitting the corals with 8 bulbs worth of Blue Plus, Superblue, and Actinic light for 10.5+ hours a day, and then turning on four Purple bulbs for 6 hours or so of viewing time. I noticed a lower level of polyp extension and less growth on the glass with this approach but something just wasn't right with the corals. They were growing but the growth tips just receded in an unsatisfactory way.
I changed the photoperiods back to four blue bulbs for 12 hours and the full twelve bulbs on for 8 hours. After the light fell in the water I had to change some bulbs, since I was down to two good purple bulbs. I had to switch to the following: 4 superblue, one blue plus, one coral plus, one Aquablue Azure, KZ new gen, two Fiji purple and two super actinic. I had reported this a couple of days back but literally minutes later I was looking at the mix and started playing around with the bulbs.
I decided to try something based on info from Faith(flbaras) where he said his best growth and results came when he used a 1:1 mix of blue and white bulbs. I put together what was a really ugly mix using 2 New Gens, an Aquablue Special, and 3 blues in each fixture. I didn't like the look at all but I noticed a couple of corals that have not been good with polyp extension became fuzzy within a short period of time(less than an hour). Very strange.
I looked a the various spectrums I had used and the only real difference between the most blue and the most white mixes was the amount of lumens - Par was very not very different. I decided to try some variations on this theme. I had some really old purples that are way past their prime that I dug out for this test. I went to the extreme and used two Purple bulbs, an Aquablue Special, a New Gen, and two blue bulbs in each fixture. Holy moley, that was bright and way too yellow for my taste, but the corals got even fuzzier, the glass got algae growth, the sand got brown.
I left it like that for a full 8 hour photoperiod and to my eye the corals really were responding well to the mix. I couldn't look at that much yellow so I then did some tweaking. I pulled out the ABS and one Purple bulb and replaced them with a blue plus and another New Gen/Lagoon blue. Not my favorite color mix but not too bad. For the purposes of this experiment the mix produces high Lumen and high par output. I want to leave this mix in place for a week or two and see what happens.
For the number people here is the comparison(numbers from the Spectra Program):
8 blue/4 purple: 9,600lm, 415umol/s
6 blue/4purple 2 super actinic: 9,360lm, 410umols(I ran this for over a month)
4 superblue, one blue plus, one coral plus, one Aquablue azure, KZ new gen, two Fiji purple and two super actinic: 11,160lm, 434umols
Four purple, 2 ABS, 2 New gen, 4 Superblue: 14,000lm, 433umols(ugly mix)
Current mix:
2 Fiji purple, 2 New gen, 1 Aquablue Azure, 1 Lagoon Blue, 2 blue plus, 4 Superblue: 13,400lm, 447umol/s
There is more par now(+9%) but the big increase is in Lumens(+43%). Everyone ignores lumens, saying they don't matter. I'm curious if that is actually true. As always, there are lots of factors at play in the reef, so I may not learn anything conclusive. It will be interesting to try anyway