T5HO Lighting, how high above tank

The friendliest place on the web for anyone with an interest in aquariums or fish keeping!
If you have answers, please help by responding to the unanswered posts.

JackBlasto

Aquarium Advice Freak
Joined
Apr 14, 2011
Messages
324
Location
Morgantown, WV
I have an awkward tank... It was custom made and I now see the challenges inherent of this although I am SLOWLY, through trial and error, getting things right.

My tank is 36 inches high by 36 inches wide (left to right) and 18 inches deep (wall to front). A giant square facing it. 98 gallon tank

I have seven T5HO 36" bulbs in the canopy. This makes almost 2.78 watts per gallon of light... I've read all about lux, different heights etc but lets just say I have 3 watts per gallon :) I know I'm not reaching quite that because of the depth but I DO have great reflectors so I MIGHT actually be getting OVER 3 watts per gallon very easily as the HO lamps are said to be some of the better ballasts out there... Substrate is on a slope and accounts for about 7-8 inches so light needs to make it about 28 inches down to reach the substrate floor.

I have carpeting baby tears that grow more tall, than outward (I know I have read that this is because they are low on light (I do have injected CO2 and it's levels are fine on my drop checker). SO what I did was get better reflectors and drop the lights in the canopy down so they sit on top of the aquarium rather than 7 inches above the aquarium.

Question is, CAN placing these lights so close to the glass lids in there be dangerous for heat build up, etc. Should I get some small fan at walmart and throw it up on top of the ballasts or does the fan really need to cool the bulb which is not able to be viewed now that they sit on the glass? Are the bulbs fine and won't damage themselves with the heat they create?

I can see a huge light difference from adding the new reflectors and moving the lights down and I would believe that it's an extremely bright tank giving it's dimensions that have been a hurdle for me to overcome. Any advice on the proximity of these bulbs to the top of the tank and their safety (I don't want to destroy some very expensive lighting ballasts by them cooking themselves if that's possible) would be much appreciated.
 
For anyone wanting to skip all my backstory above to get to the question...

Anyone running T5HO put them right above their glass tops (1/8" above) or will this potentially cause problems?
 
I made some custom legs for my aquaticlife 2 bulb t5ho. And it sits about 1/2" above the top. It gets a little warm but it runs for 5 hrs at a time and doesn't heat the water or anything. 1/8 is pretty close... I'd leave a little room for air to circulate. But you should be ok
 
All my T5HO's sit about 3" from the water surface but I removed all my lids as I prefer open topped tanks.
 
Back
Top Bottom