This story that people say Kessil is here to substitute halides is a great joke! Most of the guys who know better and say that, which is absolutely not true, is trying to remove halides from the market to promote their sponsors, LED companies! They work hard for that and some times they believe in their own lies! Those companies are since the beginning trying to put halides down in the market saying LEDs are more efficient and so on... Too bad the halide manufacturers gave easy to them!!!!!!!!!!! There is absolutely NO LED ever in existence that would SUBSTITUTE halides, nor be actually better than halides in so many ways! Period! Either aesthetically or in actual light qualities provided to the corals, halides beat anything to the ground! Man, every minute that my life goes by that truth is reinforced in my life! Spectrum is the most important aspect of light we need for our corals. The halides are so great in producing AND distributing that right spectrum that we can compare the results with the actual sunlight. Spectrum is NOT PAR only!!! I'm talking about the spectrum of any halide bulb being from 65K to 20K, they all will have the range between REAL UV to IR. Second is intensity, which halides can give in the right amount with the right application! Strong intensity in the most safe way you can, like the sun too! As jda said... the Emerson effect is one of the keys we have now to understand that principal related to photosynthesis. I believe there is so much more we don't know to prove why halides are the king of lights, but the facts and results should be enough for decades to come. I can't thank jda enough for bringing Emerson Effect to the table!
T5s are still the most easy way to light our reefs and works like a charm over relatively shallow systems up to 24" tall. You can cover the whole surface area of the reef with the right T5s and not even worry about anything! No LED will substitute T5s! They can try to mimic, but you will see the huge difference in the long run, period! Halides and T5 combos are the very best IMO. But halides are always the primary source and the T5s are supplemental, logically.
I love when jda comes to write here! There are only few guys who can tell the truth of the matter! This new generation of sponsorship and Youtube channel is most of the time disgusting to say the least with artificial and superfluous junk for sale and promotion. Oh man...
My recommendation here goes to keep the T5 covering the whole surface area of the tank if it's equal or less than 24" tall. If you want to have the AMAZING shimmer from halides, you should get a halide system and put some T5s on either side, if you want. Giesemann Spectra is the best fixture you can order today to achieve that result! You need to order directly form Giesemann because BRS removed all their halide gear from their web site. I actually called them when they decided to remove the halides and they told me they were not selling halides and there was no shelf space available (???). LOL! I told them how Hamilton and ReefBrite were both selling all their halide gear to the point they actually had to produce almost the entire inventory to keep up with their sales. I also told them that public aquariums were ditching their LEDs and going back to halides because of unpublished research proving superior qualities, specially in regards to spectrum. I even recommended BRS to at least try to display the halide gear and ship from manufacturers, if the problem was shelf space. I asked if the reason was to promote LEDs for easy profit and they denied, of course. By the way, that day I wanted to talk directly to Ryan, but the guy on the phone said he has no direct line. Poor Ryan... Sorry, hard to believe!!!!!!!! To me it's a marketing strategy to sell LEDs and have their great upgrades every year... Why am I writing all this here? Just to vent and teach the newbies that come to this forum and see only LED threads as it would be the best thing... They all work and have their own way to be applied . Results won't lie, though! You can most times go much cheaper with halides and have the amazing unbeatable results!
Here is that video jda was talking about:
