My whole goal is to keep people in the hobby and happy. Too many people are surprised later on when their smaller wattage/size/coverage LEDs won't do what they want in the future. Look around... you won't people with roughly 120 gallon SPS tank lighting it with only a pair of Hydra 52s although many might have started out this way would have made different choices since many are not happy that their sleek fixtures are now hidden in an AquaticLife. This has nothing to do with hatred or bias at all, just reality of people who were where are are and have gotten to where you want to go... mature SPS tanks, not just year-old tanks with frags or mini-colonies.
I quit using AI and EcoTech LEDs about the time that they merged... Gen 3 and 52 were the last iteration that I had. Had a few Razors. Atlantik v4 was the last one that I had in my home and Photon v2 before that. If I had to choose, v4 would be my choice and then Photon next (panels over pucks for me). I digress. You don't see me trying to talk you out of anything, or saying not to use this or that... just trying to give you an actual idea of what you will be up against once you get into the swing of things again. If you are budgeting a good chunk of change more more lights, then that is all that I want to impress, so good. If you think that you won't need them, then you probably should look again. Would you choose differently now if you knew that you might end up with 4x total Hydra 52s and then still 2 or 4 bulbs of T5? Even if you knew that you might need them later on, would you be Ok without them knowing that your corals could be doing better? These are not horrible things to think about.
For my conclusions, Dr. Joshi summed it up pretty well and I agree with most... no electrical savings... need about 3 Hydra 52s or xr30s to make up for each MH (2 might work in some situations). I will stay away from color and growth things. With 5 years of panel life before people upgrade, bulbs changes are no issue. Might still need a chiller in Florida or the Mojave, but heaters will run more in colder climates where heat is easy to mitigate - push for most people. I am in Colorado, any heat is a blessing, but understand that not everybody is like this. In the end, 24-26 units at $750 every 4-5 years to replace my 8 MH with no electrical savings just is not happening... to maybe do just as good of a job (again, will keep color and growth as an aside)?
Since you do have experience with other types of lighting, let me give you the MH comparison. Remember that you cannot use less wattage and get more lighting - there is no efficiency other than false manufacturer promises and message board posts. Each of those Hydra 52s are going to produce about as much light as a 150w Halide, if you indeed run them at 150w and for the same hours as the 150w halide would run (no ramping and stuff). 150w Halide can do Ok with a SPS tank with mostly MBP&S and a few well-placed acropora, but they also have better coverage (reflectors) at the cost of no programming, color control or thunderstorm (if you are into that stuff). Neither will work well alone if you want acropora all over the place, which is why 250w Halides are used moreso than 150w for SPS tank and people add a xr30 or 52 for every foot. 150w halide is a great mixed reef light for a 24x24 area just like a single Hydra 52 might be.
Regardless of what you think, I am not a hater, just have a lot of experience with all of this. I am not some dogmatic old timer who is against all new things. There are real challenges that you are going to encounter, so if you don't want to hear them, then I can just step away.
