A friend of mine has a beautiful tank SPS (with some LPS) using T5 and LED hybrid. Cut your electical and heat.

I think a lot of people get into problems when switching the lighting on an established tank. Even if both technologies work there will be differences in spectrum, intensity, spread which can negatively affect the corals. This is why when switchig lighting you should go slow, better to let some corals get a little darker/brown than bleached, and slowly raise intensity.

switch to two x 250watt mh bulbs

With the cost of electricity sky rocketing I would much rather use good quality LED's than run 650 watts of MH and a chiller, unless you have the money and don't care about power costs. IMO

I noticed no difference in my hydro bill for the year I ran LED vs MH. And my chiller was still needed.

I run three mirtras on a 62" x 32" x 32", there are certainly some SPS species that just don't do well for me but my water chemistry is far from perfect. LPS do really well provided you don't burn them with too much light and I'd say overall color is better compared to M/H only while fairly comparable to M/H&T5 setup. SPS growth appears to be quite low overall, especially for acropora. Clams do great in the sand bed.

They put out no heat into the tank as far as I'm concerned, I've measured the power from my heaters and it's virtually the same throughout the day and night when the room temp is kept stable. 80°F is almost 27°C so if you're still needing a chiller with LEDs you have other issues like inefficient pumps or an elevated room temperature. Also watts are watts and calculating electricity savings is elementary math. There is either is saving potential or there isn't, it will vary by application but it's not a myth or witchcraft.

There are advantages and disadvantages to pretty much anything you look at, for me LEDs have too much advantage to ignore but it's obviously just an opinion.

My advice is look at higher end fixtures like ATI or GHL. Other fixtures may fall short of expectations and not last as long as you would hope.

I think the math to calculate the watts with LED is a bit more complicated, as the ramping up and down would be tough.
Where my MH were on for a set period, my LED were on 24/7, but at varying levels.
My heat issues were specific to my installation, canopy in a warm room. Not all installations would retain heating issues. I suspect most would not.

Overall though, I saw no noticeable change in my bill over the 12 month period.

And while I prefer MH and am going back that way, LED does offer features that are hard to ignore.

Not really, it's area under the curve of watts vs time multiplied by the electricity rate, still simple math. Regardless how complicated you want to make it if you're LEDs are rated at half the power of the halides you could expect about half the consumption, if you ramp them up you probably don't need them to peak at 100% for the same time that you previously ran halides for. Most people also rarely run them at 100%.

In the grand scheme of things saving a hundred watts or so applied over a few hours isn't overly significant. LEDs certainly don't save people money.

Simple to who?? :razz:

But ya, not a big savings over a year. I will concur that there may be a lot of reasons to change to LED, but saving money isn't one of them!

+1.

I have tried almost every brand of LED's and came to the conclusion that there is something missing in the spectrum that corals need to get optimal coloration.

We actually just downgraded from LED's to MH and it was the best move I ever made.

With that said, LPS seem to do just fine under LED. SPS, not so much.

lol, well like I said it's elementary math so ideally simple to anyone who's completed that level of education and cares to remember it.