mh vs pc
- Thread starter Wet Paycheck
- Start date
If you have a specific situation, then people can probably help better, but generically...
PC is very inefficient. They are full spectrum. Bulbs can be hard to get. They can light a very effective tank if you have enough - the output is quality. If you are just talking watt for watt, they are probably the worst choice out there. They are also hard to reflect by design.
MH is still the gold standard for aquarium lighting and nearly all of the best tanks and most serious growers in the world still use them as at-least the foundation for their lighting if not 100% of it. They have IR and can heat your tank - for my larger tanks, this is a HUGE benefit, but not so much for tanks under 50, or so, gallons. They really help to offset my 3000W of heaters. Particularly in large tanks, can spread MH wider and deeper than most other lights and they can end up being cheaper. 150W metal halide is an awesome light that not enough people use that can work well for all by the highest light tanks and is quite efficient.
T5 are efficient and have many, many bulb choices that yield very reliable and trustworthy results. You can really tune and swap out bulbs to meet almost every need. VHO (their bastard cousin) are nearly the same but with twice the wattage and twice the output as a T5 bulb - but there are less than a dozen types of bulbs (I think still) on the market. Both T5 and VHO setups can be really good with good reflectors or really bad with cheap reflectors... same with ballasts... but quality. T5 are a really good choice if you were previously thinking PC.
LED are still not truly full spectrum and cannot still do everything that T5, MH or even PC can, but you might not care. There are plenty of people with LED lit tanks that know that they don't have the color that they could get elsewhere but they don't care and are plenty happy. You can mess with these and control them, but this is for you and not the coral (can be a detriment to the coral if you are dumb). Some people really like that you can put on lightning shows and jack around with the color, but it is not of any consequence. You can get some really low-wattage LEDs that will cut your monthly costs, but you also could just use lower wattage MH or less T5 or PC and do the same thing, so this argument always has been stupid. The diodes can last a long time, but there are many, many people who upgrade fixtures more than I change my MH bulbs, so they might not be any savings there.
If you went to Dr Joshi's talk at MACNA last year and followed his later posts and stuff, there is no real efficiency in light output other than PCs being really inefficient. It takes just as many watts of LED to put out the same output and spread as a MH or 8-10 bulb T5 setup. He had to use more watts of LED to even get close to his MH output and the color was still not as good. He did, however, have his chiller run less. His thoughts are not as deep with T5, but they are likely in the middle somewhere with heat - don't fool yourself, PC, T5 and VHO do put out heat. A 8 or 10 bulb T5 setup over my tanks would still be about the same power as the 600W (with ballast cost) MH... but the heaters would have to run more with the T5s.
Lastly, any really good quality setup of any of the above can probably crush a low quality setup of another type. Buy quality stuff after you make your choice. I really love MH, but I would tell anybody to use anything that they found at the thrift store before buying an Odyssea or some cheap china fixture with horrible ballasts, terrible reflectors and who knows if the glass keeps enough of the UV light out.
PC is very inefficient. They are full spectrum. Bulbs can be hard to get. They can light a very effective tank if you have enough - the output is quality. If you are just talking watt for watt, they are probably the worst choice out there. They are also hard to reflect by design.
MH is still the gold standard for aquarium lighting and nearly all of the best tanks and most serious growers in the world still use them as at-least the foundation for their lighting if not 100% of it. They have IR and can heat your tank - for my larger tanks, this is a HUGE benefit, but not so much for tanks under 50, or so, gallons. They really help to offset my 3000W of heaters. Particularly in large tanks, can spread MH wider and deeper than most other lights and they can end up being cheaper. 150W metal halide is an awesome light that not enough people use that can work well for all by the highest light tanks and is quite efficient.
T5 are efficient and have many, many bulb choices that yield very reliable and trustworthy results. You can really tune and swap out bulbs to meet almost every need. VHO (their bastard cousin) are nearly the same but with twice the wattage and twice the output as a T5 bulb - but there are less than a dozen types of bulbs (I think still) on the market. Both T5 and VHO setups can be really good with good reflectors or really bad with cheap reflectors... same with ballasts... but quality. T5 are a really good choice if you were previously thinking PC.
LED are still not truly full spectrum and cannot still do everything that T5, MH or even PC can, but you might not care. There are plenty of people with LED lit tanks that know that they don't have the color that they could get elsewhere but they don't care and are plenty happy. You can mess with these and control them, but this is for you and not the coral (can be a detriment to the coral if you are dumb). Some people really like that you can put on lightning shows and jack around with the color, but it is not of any consequence. You can get some really low-wattage LEDs that will cut your monthly costs, but you also could just use lower wattage MH or less T5 or PC and do the same thing, so this argument always has been stupid. The diodes can last a long time, but there are many, many people who upgrade fixtures more than I change my MH bulbs, so they might not be any savings there.
If you went to Dr Joshi's talk at MACNA last year and followed his later posts and stuff, there is no real efficiency in light output other than PCs being really inefficient. It takes just as many watts of LED to put out the same output and spread as a MH or 8-10 bulb T5 setup. He had to use more watts of LED to even get close to his MH output and the color was still not as good. He did, however, have his chiller run less. His thoughts are not as deep with T5, but they are likely in the middle somewhere with heat - don't fool yourself, PC, T5 and VHO do put out heat. A 8 or 10 bulb T5 setup over my tanks would still be about the same power as the 600W (with ballast cost) MH... but the heaters would have to run more with the T5s.
Lastly, any really good quality setup of any of the above can probably crush a low quality setup of another type. Buy quality stuff after you make your choice. I really love MH, but I would tell anybody to use anything that they found at the thrift store before buying an Odyssea or some cheap china fixture with horrible ballasts, terrible reflectors and who knows if the glass keeps enough of the UV light out.
To your question not even close, mh are much more effecient than pcs at producing light. If you are just looking at say a 50 wt mh vs a 50 wt PC then it woudl come down to the conversion factor of each ballast to say which one will be better but either way it will be close though for the same amount of watts the Mh will be producing a lot more light.
