[lauraleellbp]

Consider light to be the gas pedal, and CO2 + ferts are the gas that drive plant growth.

If you put 2 T5HO bulbs over this tank without running CO2 and dosing a comprehensive fert regimen, it'll be like flooring the gas pedal on a car with an empty gas tank. It's not going to go well.

IMO your key choice at this juncture is whether or not you want to run CO2 on this tank. Dosing Excel every day rather than running CO2 is going to get tedious as well as pricey fairly quickly.

 

[lauraleellbp]

What exactly do you mean by "medium"? The differences between "low," "medium," and "high" tech tanks really aren't exactly agreed upon, so I guess what I'm trying to ask is- what are your goals with this tank? What EXACTLY is it that makes you want "medium" rather than "low" if you don't want to run CO2?

What light fixture do you have going right now, and what do you want different from your plants/tank?

If we can get a clearer picture of what you're aiming for, then we can give better advice on how to get there

 

[lauraleellbp]

Hi Thomas!! :bounce:

Spend some time in the low tech forum- you'll find that you do have a lot more plant options than just Anubias and Java ferns even without running CO2. There are a also few species that will carpet in low light- a few small chain sword and Sagittaria species (though it's sometimes hard to find the species that stay 2-4", they ARE out there), Marseila minuta, and Lilaeopsis mauritiana are all options.

All of the tanks in my signature were set up low tech, low light, no CO2. 29gal on the left, 46gal in the middle, 90gal on the right. On the 29 and 46gal I ran the older brand of these fixtures: Amazon.com: Aqueon AQE40201 T5 Dual Strip Lighting Hoods for Aquarium, 30-Inch: Pet Supplies

 

[lauraleellbp]

The old WPG guidelines really only apply to the older T8 and CF fixtures that aren't used nearly as much these days. A T5HO fixture with a decent reflector behind the bulbs can easily produce almost 2x the usable light at substrate level as those older fixtures.

Have you already purchased the Odyssea? If so, you can probably work with that and not need CO2, if you take other steps to reduce the light- such as suspending the fixture higher up off the tank or using something to obstruct some of the light, such as mesh, floating plants, etc.

If you haven't purchased the fixture yet, and want the option of possibly going high tech with your tank down the road, then I'd encourage you to consider three bulb fixtures with the bulbs on different switches (giving you the option of running any combo of 1, 2, or 3 bulbs at a time). Not sure what all is on the market with three bulbs ATM, but I know Catalina will custom make one for you for a very reasonable price (I happen to really like these fixtures, personally... I have no affiliation with the company, however lol): http://www.catalinaaquarium.com/store/index.php?cPath=71_136&&page=1

I'm not a big fan of Odyssea brand... but I do hear they've gotten better quality than they were back when the ballasts used to constanty go on the fritz?

 

[lauraleellbp]

If you're retrofitting a hood, you need to be careful about sticking full fixtures in there, as many will overheat unless you also boost air circulation by adding in some computer fans or something along those lines. Retrofit kits don't tend to be cheap, but would probably be the safer way to go?

If you want to stick with low tech (at least for now lol) then I think 2x 21 watt (which would be T5NO rather than T5HO) would be a good choice.