non-CO2 lighting options for 75 gallon tank


Junior Poster
Jun 19, 2009
Hi. I'm thinking of upgrading the lighting on my 75 gallon tank while staying in a non-CO2, low light range. I'm having trouble deciding what to do.

I currently have 110 watts of PC lighting in an All-Glass fixture with a boxy aluminum reflector. The tank is rather dim, but I like the GE 9235 lights that I use with it.

I'm having trouble deciding between the following options:

1) AH Supply 2x55w retrofit kit. This would keep me at 1.47 WPG, but put more light in the tank than my current reflectors.

2) Catalina 3x54w T5HO fixture. I would likely just run 1-2 bulbs, but have 3 available in case I need it in the future.

I'm not concerned with the cost differences between the 2 options. I like option 1 because I can continue to use the GE 9325 bulbs. I like option 2 because of the greater flexibility (run 1, 2 or 3 bulbs).

Would both of these options keep me in a low-light, non-CO2 range? I've done lots of reading over the past couple of weeks, but can't get a grip on this. My fear is that either option would be too much light and I'd have to add CO2. I've heard people say that one T5HO on a 75 gallon tank would be high light, and others say that it would be low.

I'm aware that adding CO2 would be helpful, but at the moment I can't afford it (maybe within the next 6 months). I've considered adding CO2 instead of upgrading the lights, but as I said the tank is dim and a bit depressing so I'd like to add more light to brighten things up.

My goal is to have a rather low-maintenance tank with some low-medium light plants, including some tall grassy plants like vals. I don't want to do anything fancy, just have some healthy plants and no algae.

I currently use flourite substrate and have some java ferns and crypts, as well as a school of 17 tiger barbs and a couple of other fish.

Sorry for the long post. Does anyone have any recommendations? Am I asking for algae problems with either option? What would you do?

- John