MH vs FL/PL lights

[An2timun]

Hi guys,

I am setting up a 5 ft tank and contemplating on which light to install. Appreciate all advice on the pros and cons of these types of lighting, in terms of capacity that I need and cost that I will bare in the long run....thks

[deacon]

Metal Halide definitely gives a great light penetration and if you've noticed, the shine at the bottom of tanks have a greater beautiful glow to it. FL/PL lights tend to make it more 'uniform'. Down side is the heat generated and of course it requires greater electronic power and the bulbs will require annual replacement. So looks great but the equipment will cost, the bulbs will cost, the electricity will cost and it'll be hot, you might want to get a chiller for the tank.

FL/PL on the other hand, offers a more economic price point from purchasing to maintenance, it generates less heat especially if its coupled with an electronic ballast. Also, FL/PL lights will have a greater life span coupled with a electronic ballast.

IMHO, a 5ft planted tank would look great with metal halides. Of course, it doesn't mean that a tank using FL/PL won't look great. For me, MH tanks just have a extra "thing" to it. I Like.

[teebs]

Your lighting requirements would depend on how you want to set up your tank...

It would also be different depending on whether you want to set up a marine tank or a freshwater tank...

But for a 5ft (5x2x2) tank, you would probably be looking at around 500W of lighting capacity.

Main difference between MH and T5/PL lights is the heat produced by the lights. MH lighting produce a lot of heat and your aquarium will heat up very quickly if you do not use a chiller. Chiller wise you would probably need a 1HP capacity chiller.

Another major consideration is that MH lights cost a lot more than T5/PL lights.

[An2timun]

if 500w is required then i will need about 7 tubes of T5 bulbs right?..1 tube 5 ft is 80w if i am not wrong..this is my assumption..
(correct me if i am wrong)
7 tubes x 80w = 560w = 0.56kw
say 12 hours on all day = 0.56 x 12 = 6.72kw
July to Sept electrical Tariff = $0.1928(/h/kw) x 6.72 = $1.295 per day
so monthly additional lighting bill for only my tank lightings = $1.295 x 30 days = $38.86...
This is only the lightings...if i were to run chillers/filter pumps then this will increase....are there any other alternative?...
say if i use MH with a lesser watt..will it help reduce my power bill and still maintain a balance tank?...thks guys

[dnsfpl]

mh is very very hot, t5 is much more cooler
for better t5 lighting, use a retrofit set
more tubes can play with different colour temperature

don't forget LED, its the in thing now

cheers

[Shaihulud]

Metal halide is much more energy efficient, it produces greater lumens given the same wattage as a fluorescent light. wattage is the measurement of power consumption, 500w mh and Fl will use up the same amount of energy. Mh lamps has a longer lifespan and gives better consistency throughout its lifespan than a fluorescent lamp.

[lyan]

mh is very very hot, t5 is much more cooler
for better t5 lighting, use a retrofit set
more tubes can play with different colour temperature

don't forget LED, its the in thing now

cheers

I think u are right. Take T5 u will save more that expected. It have all the different light ray bulb to your tank.

[An2timun]

Thks guys...i'm setting up a planted tank...think i'll go for the T5s...like
the MH look though..but too x la...and the heat..dont know if i can
handle...will 2 wpg be enough for plants?..any nice setup i can follow?
dont want to be too high on the electric bill...my wf will kill me...

[Cross]

What is your tank depth. if its 2ft t5ho cannot penetrate. Mh will be the only solution. Depending on what kind of plants you are intending to culture, your lighting needs would vary. Wpg is not necessarily good form of measurement

[An2timun]

if its 2ft t5ho cannot penetrate. Mh will be the only solution.

As a matter of fact, mine is a 5x2x2....
is that so...then i will need to reconsider.

Depending on what kind of plants you are intending to culture,

i have not decided as yet...

Wpg is not necessarily good form of measurement

u think so...i read about this alot..and they emphasize that these are the basic plant needs...

[christopher.wtc]

Go for MH bro if your tank is more than 2 ft as what bro Cross mentioned, you won't need 500 watts of lights. 2 bulbs of 150 watts MH will be sufficient for a 5ft. The catch is, you might want to use CO2 if MH is used.

[o2bubble]

Get a set of good quality (e.g. OSRAM or PHILIPS) T5 HO tubes and they can easily match the performance of MH and light penetration. However, the shadowing and shimmering effects from MH is unmatchable even by LED. If you can afford to pay slightly higher maintenance costs (est. $60 to $80 for 5 ft tank) and the outfront costs of MH and chiller (est. $600 to $2000 for 2nd hand depending on china to german/italy made), get MH.

[deacon]

Yeah lah, easily settled, just get tubes since its 2ft deep only. Will have enough light, won't burn hole in pocket and wife won't kill you. Can forget about the shimmering. haha.

[Jaykit]

Stumbled across this thread while searching so some of the exact same answers. I have a couple more questions concerning MH lighting.
Is there any certain brand of MH light that is better than the others? What is the recommended height above the top of the water for them? Given that they give off alot of heat would a chiller be needed to maintain 76 in a planted tank?

[Shadow]

What do you mean by better? are you referring to plant growth, spectrum or life time?

In Canada, chiller probably not needed but in Singapore where the ambient temperature almost 30 degree C all the time, you will be glad to have chiller.

[christopher.wtc]

Stumbled across this thread while searching so some of the exact same answers. I have a couple more questions concerning MH lighting.
Is there any certain brand of MH light that is better than the others? What is the recommended height above the top of the water for them? Given that they give off alot of heat would a chiller be needed to maintain 76 in a planted tank?

I would say the good brands comes with higher price less you DIY it. Some important parts of the light set that you should consider be it DIY like the quality of the ballast and bulb, the reflective mirror that reflects light back into the tank. Design are a preference.

In my opinion as a general guide line, a 150watt bulb ratio 2ft to 2.5ft tank length, hung at 20cm above water surface, given that your tank is 2ft and below of height. This gives optimum light coverage. Different tanks requires different intensity of light, You may have to adjust the height frequently till you get it right. I would note for plants health and dust algae during this adjustment period. I do suggest CO2 fertilization when MH are used.

[Jaykit]

I will have ferts and CO2 running on the tank which is 72"x24"x24". Is it super imperitive that the mh's have built in fans or is it possible to run without them and not have any adverse effects on your tank with the recommended 20cm height? Compared to a 72" T5HO light fixture how much more would it cost to run 3x150w? Is it possible to run just 3x150w mhs or would you also recommend some other cf or t5 fixtures as well?

[dannyfish]

Get a set of good quality (e.g. OSRAM or PHILIPS) T5 HO tubes and they can easily match the performance of MH and light penetration. However, the shadowing and shimmering effects from MH is unmatchable even by LED. If you can afford to pay slightly higher maintenance costs (est. $60 to $80 for 5 ft tank) and the outfront costs of MH and chiller (est. $600 to $2000 for 2nd hand depending on china to german/italy made), get MH.

hi

Where got find osram or philips tubes?
Thk

[Goondoo]

I seriously wonder how many of you complaining about the heat actually had direct experience with MH. I was using 2 x 150w Industrial MH on my 4x2x2. I was only running a AC fan then and had never exceeded 29 degrees C. Infact, I could hold the lamps with my bare hands after 8hrs operation.
I suggest members do not comment like they know based on hear-say alone or soon all rumors will become part of the religion.
My humble thoughts.

[Goondoo]

For those considering using MH, DO NOT calculate based on 3wpg rule or you would have problems coping with CO2 and nutrients and your plant grow like weeds. If I would to set up a 4x2x2 again, I would most likely be using 2 x 75w unless I am very free maintaining the tank.
Again, just my thoughts for your references.