[pyrrolin]

I have two 90 gallon tanks, one has dual t5ho, so 108 watts total. The other has quad t8 so 128 watts total.

Does the two t5ho penetrate better than the 4 t8 even though it is lower watts total? This is assuming reflectors are equally good to make things even.

Wondering if I should look into replacing the quad t8 with dual t5ho or not.

 

[jimmyjam]

I would say the 4xt8 still beats it assuming they are new bulbs/same age

 

[pyrrolin]

the t5ho tank looks a bit brighter than the t8 tank. Maybe the difference in quality of reflector makes that much of a difference.

 

[Y2KGT]

This chart should help. As you can see even the 2 bulb T5HO fixtures differ significantly from one manufacturer to another. The Hagen Glo are the best fixtures in my opinion and it's because of the reflector.

I Use the single Hagen Glo T5HO on all 4 of my display tanks.

Hint: the higher the Lux the better and the higher the Lux per Watt the more efficient.

http://www.petsandponds.com/en/aquarium-supplies/c5813/index.html
--
Paul

 

[solarz]

The T5HO are better. T8s are bulkier, so more of their light output is blocked by their own bulk. T5HO tubes are slim, so more light is reflected down to the tank.

 

[jimmyjam]

def all depends on the setup, but if your comparing say phillips daylight 2xt5 vs 4x t8 phillips daylight with same reflector then t8 wins hands down. But There is a huge difference on reflectors and ballasts in both types of lighting. I guess the question remains. What are you looking to do ? lol Im guessing your looking to keep both fixture that you currently have.

the t5ho tank looks a bit brighter than the t8 tank. Maybe the difference in quality of reflector makes that much of a difference.