# 3X36w T8 is brighter than 4X54w T5s. Wha.?



## googz (Apr 27, 2006)

Hi,
I have a 4ft 55gal planted tank (with Anubias, Java ferns, glosso and a few others using DIY co2) that was lit up with an old 3 X 36w T8 fixture using magnetic ballasts. 
After reading through the forums I decided to update and put in an electric ballast 4 X 54w T5 fixture.
Well, it arrived with 4 Actinic globes which I promptly replaced with 2 X Sylvania GroLux, 1 X 10000K aquastar and 1 X 6500K (all 54W). 
After switching it on I was extremely disappointed by the amount of light it produced. 
It was actually noticeably dimmer than the old T8 unit and all plants ceased to pearl with the bases of my java ferns now turning brown to low light (first issues in over 2 years). 
Can anyone here explain why 108watts of T8 (with white paint as a reflector) is brighter than 216watts of T5 (with a polished reflector), am I missing something? 
Thanks in advance!


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## Laith (Sep 4, 2004)

That doesn't sound right... what is the make/brand of the light?


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## googz (Apr 27, 2006)

thanks for the reply, I thought it wasn't right...
It is a Mercury LC-120 which I cannot find much info on. (looks to be the same as a Weipro LC-120)
Is it possible that it shares ballasts between 2 lights or something like that, which would cause it not to emit the entire 54w per globe?


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## goalcreas (Nov 20, 2006)

are you sure you got High Output ballasts.
You could have gotten T5 Normal output ballasts by mistake or they gave you the wrong ones and even if you put the HO 54 watt bulbs on it you will end up only with 1/2 the (27 watt) output.
I would check the ballasts, because my T5 HO's are so bright, I only run 2 of them all day and the other t2o for a short mid day blast.


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## googz (Apr 27, 2006)

I just pulled the light apart and the ballasts are 2 X Jamicon 108W total. So yeah they are 54w ballasts. Any more ideas? could the reflector make that much difference? it is a polished single reflector for all globes.


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## Mud Pie Mama (Jul 30, 2006)

I still agree that something does'nt 'jive'! I am unfamiliar with the Sylvania GroLux; what is the K rating and is it rated for H.O.?


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## googz (Apr 27, 2006)

The Groluxs are rated at 3400K (mainly used in hydroponics). I dont believe this to be the cause though, as in the T8 fixture I have one of these (1 X grolux, 1 X 6500K and 1 X 9350K) which is almost the same temperature bulbs as in the T5.


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## chiahead (Dec 18, 2004)

Something must be wrong with the actual T-5 unit you bought....every T-5 unit I have bought including both HO and regular are much brighter than T-8 units. By design of the bulb, ballast and reflector it should always be. So, either its the ballasts in the unit, or the bulbs themselves. My vote is for the ballasts. Just because they are rated correctly does not mean they are doing what they are rated to do.


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## googz (Apr 27, 2006)

chiahead - Thanks, sounds like the most logical explanation...
Does anyone know any way of testing the globes or ballasts (without buying more, I cant justify spending much more without a guarantee that they will become brighter and usable)


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