Switching from LED to Metal Halide

[DSC reef]

I am hanging my halide T5 fixture today. I haven't used either in 8 years so I'll be happy to provide an unbiased review. I have been using LED for years, with phenomenal growth, color, and coral health. But I'll try any light and will use what works the best. I have zero bias towards any technology. I carry kessils because it is my favorite LED. I carry halide bulbs because they work. If I could I'd carry the pendants and fixtures too.

One of the many reasons why I like your reviews @BoomCorals

 

[rtparty]

Even though it is considered the gold standard of lighting (for a reef), it comes with some baggage. Namely the heat that they give off can cause temperature issues for tanks in hotter climates requiring the use of a chiller. The other is the cost of operating MH systems. The bulbs need to be replaced every 6 - 12 months to maintain PAR and the desired spectrum. They also are less efficient than LEDs due to the energy that is radiated as heat. This increases the energy costs. If a chiller is called for, then that adds to the cost as well.

So that was the cons, the pros are that they are dead simple to use. They have great spread (due to the reflectors), and they grow and colour up coral really well.

Dennis

Total myth that halides should be replaced that often. Quite a few studies and tests show that there is very little spectral change and/or PAR drop even after 24 months with most halides.

What will really shock people (it certainly shocked me) is BRS' T5 testing where an 18 month old bulb had the exact same spectrum as a brand new bulb. I've spent years and years testing T5s and relaying info over on RC. Unfortunately, I never tested the spectrum (didn't have the tools or money) since even the professionals accepted T5 bulbs shifted after about 9-12 months. If that "theory" is debunked, it just killed another common myth: that LEDs save everyone money.

 

[BoomCorals]

My personal opinion. I've never looked at LED as a cost savings. Nor do I ever bring up cost as a factor. If you're looking for a tiny bit of cost savings, you're in the wrong hobby.

 

[Crabs McJones]

My personal opinion. I've never looked at LED as a cost savings. Nor do I ever bring up cost as a factor. If you're looking for a tiny bit of cost savings, you're in the wrong hobby.

When I first got into this hobby, a friend of mine said that you're not ready unless you can take a $100 bill and light it on fire and be just fine with it.

 

[DSC reef]

Thank you @rtparty and @BoomCorals. Couldn't have said it better myself

 

[Wankell]

My personal opinion. I've never looked at LED as a cost savings. Nor do I ever bring up cost as a factor. If you're looking for a tiny bit of cost savings, you're in the wrong hobby.

I do not have any proof, nor can I document it to compare the difference since I do not own any MH/T5 lighting fixtures any more, but I find it extremely hard to believe there is no cost savings by running LED. I have run all 3 combos and my electric bill has always been higher with MH/T5's than they have been with LED. Not to mention the added expense of having to use a chiller.

 

[Crabs McJones]

I do not have any proof, nor can I document it to compare the difference since I do not own any MH/T5 lighting fixtures any more, but I find it extremely hard to believe there is no cost savings by running LED. I have run all 3 combos and my electric bill has always been higher with MH/T5's than they have been with LED. Not to mention the added expense of having to use a chiller.

Oh there is definitely a cost savings in some aspect. He's just saying that he doesn't look at it from that perspective.

 

[KJoFan]

Ok, regarding lux meters to compare lighting when switching from one to another...if MH is giving me 40,000-60,000 lux on average in the main areas of the tank (not around the edges), and LED is giving me 25,000-35,000 lux in the brightest areas, is this comparable? Are you aiming for the same lux numbers from both systems or is there a conversion factor? (I think there is but I can't recall exactly). @mcarroll @saltyfilmfolks

 

[Velcro]

Oh there is definitely a cost savings. He's just saying that he doesn't look at it from that perspective.

It depends on how much you overpaid layed for your leds *cough* radion *cough*

 

[KJoFan]

I do not have any proof, nor can I document it to compare the difference since I do not own any MH/T5 lighting fixtures any more, but I find it extremely hard to believe there is no cost savings by running LED. I have run all 3 combos and my electric bill has always been higher with MH/T5's than they have been with LED. Not to mention the added expense of having to use a chiller.

Not every MH or T5 or MH/T5 tank requires a chiller. I use MH and I have no need for a chiller. Just saying, those two things don't necessarily go hand in hand for all users.

 

[Crabs McJones]

It depends on how much you overpaid layed for your leds *cough* radion *cough*

You should get that cough looked at! ;Happy;Happy

 

[DSC reef]

I do not have any proof, nor can I document it to compare the difference since I do not own any MH/T5 lighting fixtures any more, but I find it extremely hard to believe there is no cost savings by running LED. I have run all 3 combos and my electric bill has always been higher with MH/T5's than they have been with LED. Not to mention the added expense of having to use a chiller.

Where you live makes a difference. Not everyone has to run a chiller. Saying that you save a ton of money by switching to led is not always true and it's a justification IMO. Again, it comes down to what you like best. If you have led lights on your tank then great. Your quoting one of the least biased members on here too. Can't we just agree that both lights have pros and cons and just use what you like?

 

[Velcro]

Not every MH or T5 or MH/T5 tank requires a chiller. I use MH and I have no need for a chiller. Just saying, those two things don't necessarily go hand in hand for all users.

True that. If you’re really worried about heat, check out the coralvue lumenbright reflectors. Amazing reflector and surprisingly affordable that is designed to hang high above the tank.

 

[Wankell]

Not every MH or T5 or MH/T5 tank requires a chiller. I use MH and I have no need for a chiller. Just saying, those two things don't necessarily go hand in hand for all users.

True, but it is definitely a factor, on my largest tank a 4' 90g the T5 fixture heated up the water a few degrees too high and warranted either noisy fans on the sump with higher evap or a chiller to keep them down.

 

[Reefcowboy]

I switched to MH from Radions G4's. Nothing wrong with the leds, corals looked spectacular. I have had however the best color, growth under halides, and got the giesemann mh/t5 which looks very sleek, owing nothing aesthetically to leds.

My opinion is it all goes down to tank size, and where you live. I live in NY so only 4 months out of the year I would need to either run a chiler or fan to help with heat. The rest of the months heat would help actually.

As far as tank size, if one has a tank up to 100-150 gal, halides are fine as two 250w would be plenty of light. Replacing two bulbs every 10 months isnt that big of a deal IMO. If the tank is larger, halides play against you with heat and costs. Leds in that case are a more viable option.

Electricity bill will be even, if one wants to properly light an sps tank. With radions my bill was about the same as with halides.

Leds these days can keep corals happy, so it all goes down to personal preference

 

[Wankell]

Where you live makes a difference. Not everyone has to run a chiller. Saying that you save a ton of money by switching to led is not always true and it's a justification IMO. Again, it comes down to what you like best. If you have led lights on your tank then great. Your quoting one of the least biased members on here too. Can't we just agree that both lights have pros and cons and just use what you like?

Absolutely, I like all the options, I am unbiased as well, me quoting him doesn't mean anything to me, not sure why that matters. Just pointing out there is a savings to consider.

 

[DSC reef]

True, but it is definitely a factor, on my largest tank a 4' 90g the T5 fixture heated up the water a few degrees too high and warranted either noisy fans on the sump with higher evap or a chiller to keep them down.

How many T5 bulbs were There? I ran a 6 bulb 36" fixture over a 36 gallon and never had a heating issue once for years. There's so many factors to this equation like what temp you keep your A.C. at or where you live, ect that it throws the cooling savings out the window. Plus, heating a tank cam be costly too. Me personally, I've seen tanks with all different lighting and I appreciate them all and what they can do. I just love the look of the halide. Maybe that's why the kessils are so appealing to me?.....lol

 

[Dennis Cartier]

Total myth that halides should be replaced that often. Quite a few studies and tests show that there is very little spectral change and/or PAR drop even after 24 months with most halides.

What will really shock people (it certainly shocked me) is BRS' T5 testing where an 18 month old bulb had the exact same spectrum as a brand new bulb. I've spent years and years testing T5s and relaying info over on RC. Unfortunately, I never tested the spectrum (didn't have the tools or money) since even the professionals accepted T5 bulbs shifted after about 9-12 months. If that "theory" is debunked, it just killed another common myth: that LEDs save everyone money.

I have some plans to put that myth to the test. On my new build, I am planning an automated top down 8MP camera to do time progression top down shots on a fixed grid each day. After deciding to add (4) 250W MH to my build along with the (5) AP700's, I decided to explore adding a Seneye and a cheap spectrometer on the camera carriage. That way I can monitor for slow changes to PAR and spectrum shifts. I had planned to use T5 instead of the MH, but decided I would give MH a try since it has been almost 30 years since I bought a MH system. My last MH system came from a hydroponics store, used ????K bulbs and pre-dated reef specific systems. Back then you had to assemble the ballast yourself.

If I decide to still include an outside row of T5, then I might be able to collect data on T5 aging as well.

Dennis

 

[Wankell]

How many T5 bulbs were There? I ran a 6 bulb 36" fixture over a 36 gallon and never had a heating issue once for years. There's so many factors to this equation like what temp you keep your A.C. at or where you live, ect that it throws the cooling savings out the window. Plus, heating a tank cam be costly too. Me personally, I've seen tanks with all different lighting and I appreciate them all and what they can do. I just love the look of the halide. Maybe that's why the kessils are so appealing to me?.....lol

I'm with you, there are so many variables it's a bit silly to bicker back and forth about it. I also had a 6 lamp but it was a 48" and I didn't use the house AC to help cool the tank. Which would be another variable!

Preference, preference, preference, there's no longer an argument that LED doesn't work, so at the end of the day does it really matter? Why don't we tear each other apart about what cars we drive instead? ;Yuck

 

[mcarroll]

Total myth that halides should be replaced that often. Quite a few studies and tests show that there is very little spectral change and/or PAR drop even after 24 months with most halides.

I think one could only say that without a lot of first hand experience. While my tank was on a 12-hour schedule, corals would decline at the 6-month mark like it was clockwork. When I cut the lighting hours back thanks to the concept of Peak Sun Hours (I think at least analogous to DLI)...

...the clockwork responded predicatably and corals would decline at about 9 months.

Likewise, the level of brightness between old and new bulbs wasn't debateable....old bulbs were MUCH less bright even to the naked eye. Having a dual halide fixture makes this easy to see – switch one bulb and not the other and you get a direct A-B comparison so your brain's interpretation is trustworthy. Newer bulbs were BRIGHT!!!

Last, old bulbs LOOKED WORN OUT. The amount of carbon scoring inside the bulb always seemed phenomenal to me.

If you wanted to say that there were some tanks and some corals that could tolerate this, I'd be willing to listen and hear specifics – including what tank, what light, how high, what corals, and tank water test history.

As a general statement about all tanks, lights and corals I call one bee to be followed closely by one esse.

I've never looked at LED as a cost savings. Nor do I ever bring up cost as a factor. If you're looking for a tiny bit of cost savings, you're in the wrong hobby.

If you're looking for a tiny bit of savings switch to DC pumps.

Up Front Costs
When you (or I; anyone!) can build a perfectly valid LED fixture for less than the cost of a set of new mercury-based bulbs, I think you have to consider that. Comparisons are almost always with the highest end commercial fixtures – which I understand, but which doesn't tell the whole story.

At my DIY rate I could build a new LED fixture, use it for a year and then throw it in the trash and build another one next year and STILL COME OUT AHEAD. That's big potential savings, not tiny.

Bulb Costs
And unless you are willing to revert to Chinese no-name bulbs and pay almost nothing for power, you'll notice a bigger-than-tiny potential savings in ongoing costs as well.

If you haven't run the numbers, you should just to know for reference....it's big.

Power Costs
If you're in a hot weather state and/or an expensive electricity state, then there's even more potential as you might eliminate a chiller in the process, or at least take it from running all the time to running rarely. It makes a big difference!

In a cold room, the heater will have to work harder and harder with each efficiency improvement to keep the water tropical, which will cause the HVAC to work a little harder to keep the house cool. Bye-bye power savings in that case.

After swapping out halides for LED (300 down to 40 watts) and a Mag 7-based skimmer for a Tunze 9410 (70 down to 14 watts) I had to add two large heaters to keep the tank steady during the coldest winter months.

That said, potential is potential and nothing more – you might not net anything more in ongoing cost savings than the up-front costs.

You have to look at the details of your own case to know.

Ok, regarding lux meters to compare lighting when switching from one to another...if MH is giving me 40,000-60,000 lux on average in the main areas of the tank (not around the edges), and LED is giving me 25,000-35,000 lux in the brightest areas, is this comparable? Are you aiming for the same lux numbers from both systems or is there a conversion factor? (I think there is but I can't recall exactly). @mcarroll @saltyfilmfolks

For these purposes you just want the numbers close – no conversion to any other units is necessary. You could say the LED's are giving you roughly half the power in the tank as the halide system. (Helpful to remember these numbers are always rough and they don't need to be exact.)

Not every MH or T5 or MH/T5 tank requires a chiller. I use MH and I have no need for a chiller. Just saying, those two things don't necessarily go hand in hand for all users.

In hot climates it's not uncommon though....or anywhere the HVAC doesn't keep a steady 72ºF all year round.