I never have seen DIY as a good option for lighting. I have read time and time again from people doing a DIY on LEDs, that after time spent, learning curve, costs of mistakes, they might have bought the fixture. DIY on LEDs is just not the same as DIY on a kalk reactor. If you make minimum wage, it might pay off to do a DIY, but then again most making min wage are not going to be in this hobby long enough to pay for the LEDs anyways.
For the LED comparison, lets compare....I just feel as thought LEDs get too much hype, although I am sure in the long run they will save you a few bucks.
I am not going to even touch pros and cons of each, but I will use the fixture that seems to get the most positve ratings, the AI Sol. I do not know his exact dimensions, he says he is 200, so it is likely custom, so I will use 210g as a reference
Using AI Sols recommendations, for his tank he will need 6 unit kit, which costs $3300.
The power consumption per hour is 465. His MH is 800+ballast loss, so lets say 900.
So his difference is 365 per hour. I will use my electricity rate for comparison @ .13/KWh
So his total savings per month (assuming 10 hour day and full intesity) is $14.50. Not impressive to me at all. OK, yes you can add in bulbs, but likely you are going to have a module loss at some point over the many years it would take to recover the costs. Add in chiller? I have 3x250 MH and have absolutely no need for a chiller...one small clip on fan and keeping the room below the tank temp is all that is required. The tank is rock solid at 80 year round.
So for a grand total of $173/yr in electricity+bulbs he can have LED and save absolutely nothing. The ROI is not a year or two, it is many years.
I have run these numbers on my tank many times and the math just is not there.
Even using my DT tank as an example, 180g running 3x250w. Using same comparison.
3 unit kit $1700 using 810 and AI sol would use 228, a difference of 582 with a savings of $35.90 a month, it still would take me almost 4 years to recover the cost (not assuming bulb replacement, as I have a wild guess that bulb replacements equal out to module failures). Time will tell.
Even with these comparisons, as I mentioned before, there is absolutely no question that the tanks saved me almost $100 a month on my gas bill during the winter. I do not have a small, or poorly insulated house and my gas bills were $100 less (during deep winter months), with the heat kept higher in the house than the year previously...and it was much colder this year than last. That cost savings easily washes out any savings from the LED savings in electricity consumption.
I am just being a critic and I hope I have not offended anyone. The real math, for me, doesn't work out to the hype.