Before we get started I want to set the record straight. I did not purchase the joe the coral acro, it was a gift. I would not have purchased this particular acro since it does require higher lighting. I did purchase the red planet as I was told it did well in lower lighting. I also purchased the other sps that I am having issues with as well, but everyone seems hung up on the acros. The ORA monti is just about totally bleached out at this point and I don't believe anyone has even addressed it.
I have had the acros and ORA monti for less than two weeks. I know some people take much longer than two weeks acclimating in a lower light area of the tank, so I do not personally believe reduced lighting would result is starving the coral in such a short period of time (especially considering how much I feed and the available nutrients in the tank), but I may be wrong.
The other sps (red digitata, red monti cap, green stylo) appear healthy besides the lack of PE and growth over a couple of months.
Let's get started!
Well, I didn't really feel like taking the time to justify my reasoning, but as it seems like some are getting hung up on the lighting...here goes.
First off, in my first post, I originally estimated the sps were receiving 150-220. That was just a ballpark from what I remembered when I first did my research. I then revised it to 180-200 at the most. My sps are at 9 inches directly underneath the light and as high as 7 inches deep not directly under the light.
Here is how I came up with those numbers.
LUX:
While I don't really think the lux-par conversion is great, it's the only light measurement tool I have access to, so it is what it is. Lux at the surface of the water reads 40,000. Using Dana Riddle's new article, at 9" deep, the par value should be approximately 26.7% of that. Using a conversion factor of 60 (I decided on 60 after researching, at length, lux to par conversion with LED's), that bring us to....
178 par. This also coincides with the readings I have taken at that depth with the meter.
BRS info:
I'm not sure if everyone realized this (it's ok, I know my first post was long) but I have 3 of the Kessil A160's mounted 12 inches apart, center to center. The sps are underneath the center fixture, but they are also receiving light from those other two fixtures. These are charts of par readings done by BRS from 3 A360's mounted at 8" from the surface, 12" apart.
If you average the 6 center par readings, you get 387 at 6" and 283 at 12". Since 9" is directly between those readings, that comes to 335 par. The A160's have 40 watts to the A360's 90 watts, so A160's are 44% the power. 335*.44=
147.4. The problem is that this is assuming a mounting height of 8", where my lights are at 6.5". I have also read that the A160 may have a narrower lens, which would increase par slightly, but I have not been able to confirm this.
This is where things get a little more speculative.
I forgot to copy the graphs from the video, but BRS measured a single A360 at 6.5" vs 8". If you average the center 4 par readings here is what you get.
Mounted at 6.5" - 300 par at 6" depth, 161.5 at 12" depth.
Mounted at 8.0" - 241 par at 6" depth, 136.5 at 12" depth.
To be honest, I may not have the math perfect on this, but if you average it out, do the conversions, etc. it comes out to about 15 more par at a 9" depth which comes to
162 par at a 9" depth.
Having reviewed the data, I will correct my assumption to
160-180 par.
Is that still less than ideal for acros? Yes, it is, but take a look at this thread.
https://www.reef2reef.com/threads/whats-your-lowest-successful-par-level.327468/. You can see numerous accounts of people who were/are growing various types of sps (even some acros) under far less than 160 par.
I would love to use a par meter to double check these assumptions, but as I have previously stated, I cannot afford to buy one atm, and I do not have access to one (BRS rentals are out of stock, no local club, LFS doesn't rent them).
That's all I have for now! I hope I have made a compelling case for my reasoning and if not, well I hope you at least enjoyed the post!