# T5HO distance



## Bacon (Jan 29, 2013)

I'm almost done setting up my aquarium, all I need to do is mineralize some soil and setup a canopy for holding my light fixture.
I had an Odyssea dual 54wt 48" T5HO fixture with a ballast but I decided to strip the wiring out of it and mount the bulbs(Grabbed a Giessemann Aqua Flora and Midday) inside a diy canopy.
The distance from the top of the tank to the substrate will be about 19" to 18"(Standard 55 gallon height is 21").
Now my question is how high above the substrate should the lighting be for hi light with the use of CO2?
I need the measurement to make the canopy hold the bulbs at that height.


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## Adam C (Feb 7, 2013)

Will there be reflectors? Reflectors (per tube, or dual) can increase par drastically.



Bacon said:


> I'm almost done setting up my aquarium, all I need to do is mineralize some soil and setup a canopy for holding my light fixture.
> I had an Odyssea dual 54wt 48" T5HO fixture with a ballast but I decided to strip the wiring out of it and mount the bulbs(Grabbed a Giessemann Aqua Flora and Midday) inside a diy canopy.
> The distance from the top of the tank to the substrate will be about 19" to 18"(Standard 55 gallon height is 21").
> Now my question is how high above the substrate should the lighting be for hi light with the use of CO2?
> I need the measurement to make the canopy hold the bulbs at that height.


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## Bacon (Jan 29, 2013)

Adam C said:


> Will there be reflectors? Reflectors (per tube, or dual) can increase par drastically.


Whops! Forgot to mention I will be using the reflector that came with the light fixture, it seems like a fair reflector showing multiple images of each bulb in the reflection, so a single reflector.


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## Adam C (Feb 7, 2013)

I would assume that if you have the bulbs 21" (18" from substrate plus 3" in the hood), you will likely be in the medium range. When I checked par values on my 40b at ~18" from substrate, the 4xT5HO deliver about 115mmol. 

It should also be noted (for others since you are using quality bulbs) that bulbs can make a very big difference in light output. I tested 4 bulbs and found Wavepoint's Tropwave delivered around 25% more par over the Corallife bulbs tested.


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## Bacon (Jan 29, 2013)

Adam C said:


> the 4xT5HO deliver about 115mmol.
> par over the Corallife bulbs tested.


Are you talking about the 36" quad bulb model from Odyssea and are you using the ballasts that came with it?
I have found out that the ballasts form Odyssea fail to drive the bulbs at T5HO rating and more near T5NO ratings. On my home computer I have a link to the article where the ballast internals (Very inefficient and made cheaply) were replaced with a Work Horse model which raised the light levels dramatically.
Also I plan to grab some highly polished aluminum single bulb reflectors in hopes of getting as much light as possible to the plants.


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## Adam C (Feb 7, 2013)

Bacon said:


> Are you talking about the 36" quad bulb model from Odyssea and are you using the ballasts that came with it?


Sorry, I should have specified; I use 2x dual T5HO fixtures. One is Aquatic Life and the other Corallife.

I have another 40b that I use to grow plants and breed GBRxEBR and Peacock Gudgeons where I installed a 36" dual t5no from HD at 21" from substrate. Par values were low on this system until I added a reflector. Same holds true on a 20L with HD ballast. Quality reflectors can go a long way.

Mind you, it is a lot easier to maintain a tank at lower light levels than it is at higher light levels. And without having a par meter to test them, its really just a guesstimate about your levels.

If you google "par versus distance," you will find a good chart to get an idea of light levels.


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