t5ho lighting Q


Junior Poster
Feb 28, 2009
nevada city, nor cal.
i have a thirty gallon tank not getting enough lite with its current setup and im going to get a fulham ballast with t5 hos. i was wondering how many 39 watt t5 bulbs would be enough? and whats an ideal bulb for growing? im looking into getting some glosso as well and i know they need high light. what do all you gurus out there think?:)

ive got.
amazon sword
star grass
java fern
singapore moss on logs
jungle vall
corkscrew vall
broad leaved ludwigia


Guru Class Expert
Feb 17, 2007
Lincoln, UK
Is it T5 or T5HO? You say T5HO in the title then T5 in the post ;) These are 2 different lights.

I would say if they are T5HO you have enough. I used 1 x 30W T5HO over this 33USG:

I did however use pressurised CO2 which is IMO much more important than the overplayed 'need high light' statements!!!

I think as long as you get enough light as a good spread allied with CO2 then you are on the money really. They are high CO2 plants and not high light plants that people suggest (IMO)

What you could do is get 2 x 39W and space them in your hod a third from the back and a third from the front. Then use the one in the front for an 8/9/10 hour photoperiod with the one in the back coming on for the central 2/3/4 hours as a 'noon burst'. This would then supply a period of higher light without pushing that light all day long :)



Lifetime Charter Member
Lifetime Member
Jan 24, 2005
Sacramento, CA
Most multiple bulb T5HO light fixtures don't allow you to turn one of the bulbs off. So, for good flexibity buying two single bulb T5HO fixtures would be necessary. Then, you could space and use them as AC recommended. We do need to get away from the reef tank mindset where seeking ever higher light intensity is the goal. Planted tanks just don't need that much light, and the extra light just makes everything else be much more difficult.