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Discussion Starter · #1 ·
i'm looking up aquarium lighting and checking out alternatives to the T5HO.

and some strange ideas come to mind, ... MH (metal halide), or HPS (High Pressure Sodium)

to compare with a 400Watt alternatives (a T5HO 8 bulb fixture)

well MH is about 4000-4200K (color)
HPS is about 2000K

i'm impressed with them so far as their light intensity is higher than the T5HO (total light output for the fixture)

does anyone know of any alternative bulbs that are somewhere around 6500K (color) ?

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729 Posts
Discussion Starter · #2 ·
Halogen is about 3000K


there are some specialty 6500K varieties of MH out, but their hours, intensity, etc. make fluorescent more efficient in very area.

the more wattage on HID bulbs, the more intense, (great), but their spectrum goes back to the default 2000K or 3-4000K, not the 6500K sought for growing plants.

still searching, but so far not finding other alternatives.

and it makes me wonder about the use of lighting fixtures for aquariums that use Metal Halide HID bulbs, either just the MH or a mix, ... just doesn't seem right.

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Discussion Starter · #3 ·
in my totally unscientific testing, comparing fluorescent lights from

in rough estimates on some bulbs to get an idea what the efficiencies of various fluorescent bulbs are

a basic T5 is about the most efficient use of power
the longer the bulb, the more efficient use of power

but we don't go on efficiency when we just want the most light possible with our financial budget

a T5 2800 lumens (28 watts)
a T5HO 5000 lumens (54 watts)
a T5VHO 7200 lumens (97 watts) (memory on this one)

so a basic T5 is the most efficient
but the T5VHO does deliver the most light output currently available (in my totally non-scientific testing)

rating with a 8 lamp T5HO fixture,
40,000 lumens (432 watts)

a Metal halide has about 40,000 lumens, 400watts
but ... at about 4200K

so competitive light out per watt with the T5HO but there are better light spectrums out there

i did find a single 6500k Metal halide, ... at 19,000 lumens, ... there becomes a rather significant loss of efficiency


if any of this helps anyone out, great
if not, ... it was a personal curiosity i had that i explored :)

again, if anyone does find other lights that may deliver more intense light i'd like to hear about it :)

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729 Posts
Discussion Starter · #4 ·
Metal halide bulbs
Metal Halide Lamps - About Lighting - Training Center - Support - High End Systems

this doesn't have the typical "M" that is favored for photosynthesis, but ...

2 questions
1) i would guess this should still have enough viable light that is beneficial for plant health and photo synthesis to be beneficial and cover the plants requested spectrum
-any input on the subject ?
(still looking into this - aside from metal halide are typically either 3000K or 4200K)

2) bulb life ?
fluorescent lights, while rated for about 25,000 hours, are better to be replaced after about 1000 hours (or 6mo. about) to keep light intensity up
Metal halides, (rated at 20,000 hours) what is an effective time to replace these lights to maintain lighting intensity efficiency ???

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729 Posts
Discussion Starter · #6 ·
findings so far ...

lumens output per watt, ... looks to be about as effecient as T5HO
Metal Halide (at 400Watts) is slightly more effecient - but not enough to count

bulb life
Fluorescent - replace every 6mo to keep intensity up
Metal Halide - replace every year to keep intensity up
Induction - replace every ... 5-10 years

cost, (for 400Watts of bulbs) well prices for where i live)
Fluorescent - about $200 for 8 bulbs (4' length bulbs)
Metal Halide - about $25-30
Induction - about $200 (estimate)

light (400Watts) (lumens)
Fluorescent - 40,000
Metal Halide - 40,000
Induction - 60,000+


i see lots of promises with induction light spectrum but nothing i would bet any money on

so far i do like what i have seen for the Metal halide spectrum's more than the fluorescent spectrum's

and operational costs look to be much more reasonable over fluorescent lighting

nothing says "go get 400Watt bulb" , it's just where i started and used as a base


looking at induction lights, ... it sounds like the 200watt bulbs would be on the excessively intense for most peoples needs... well all but the most demanding plants in the deeper tank depths. (i hope i worded that right)

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Discussion Starter · #7 · (Edited)
LED or Induction

while not an expert at the moment on costs

while induction lights seem prohibitavly expensive ...
so do LED lights, ...

cost expense seems to favor induction lighting at this point
at least where intensity comes into play.

light intensity on induction lights is +50% over T5HO or Metal Halide per watt

power consumption on induction vs. Metal halide, ... there is a lot of extra power just for the ballast for metal halide

light spectrum output on induction lights uses the same technology as fluorescent lights

400Watts of induction light is equal to about a 600Watt Metal halide
250Watts of induction is almost 400 watt metal halide (still too much for most tanks)
150Watts of induction ... 200+Watts of metal halide or fluorescent
-this gets some very high light level tanks

400Watt Induction is $800-$1200
150watt induction (amazon has one for $250)

these are really hard lights to find ... and as i said earlier, prohibitively expensive :(

but ... compared with aquarium brand names, ... suddenly they're cheap, (before considering cost of maintenance/replacement)
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