Aquarium Lighting Questions!

[Danf310]

So I recently bought a Power-Glo T8 18" high intensity strip bulb. Specs are as follows:

-15w
-15,000k
-580 lumens

I have it in a ballast for a 20 gallon high tank. Is this light considered low or medium light? I've been looking everywhere for a bulb that would give me sufficient light for a heavily planted aquarium but every time I buy a bulb i'm still not getting to what is considered to be a high light, or at least a medium-high lighting situation.

I have another fixture so I actually have two fixtures. The other bulb is not as "strong" but is supposed to promote plant growth as well.

 

[mohican]

IMO, its not so much the bulb but rather the fixture. A standard t8 fixture is problem low-medium lighting. T5 Ho fixture will give u more high lighting. Depending on ur planting wants depends on the fixture to use. Ur bulbs will help with different plants and their needs. For example, java fern has different light requirements than reinecki plants.