oooohhhhh, Ok, that makes sense O_O Will 2x20 watt t8, 2 foot aquarium lights be considered "too bright" for the fish? I want to grow plants in my tank and if I dim the lights, I'm afraid it will let the plants die (So far I just Have hornwort though I'm letting them sit on the ground for now, java fern and amazonian swords... and some cobra grass)
At the Most I can decrease my total wattage by 4 watts for my lights
This happens to be the same lighting I have over the 30g in the photos, at least the latest photo. The old original ballast gave out, so I pulled all the bits out and used the housing for a dual T8 24-inch shop light. So that is not too much, but you will need decent tubes.
Can you get either the ZooMed brand or Hagen brand? Online if not locally perhaps. In the Hagen "Glo" series the Life Glo (or Life Glo 2) is the best lighting for a planted tank. It is 6700K with true colour rendition, and is high in red, blue and green. In the ZooMed series, the UltraSun is basically identical, at 6500K.
Since you have two tubes, like I now do, you can mix them. I find that either one of the above combined with a slightly warmer white works very well. This is best in the ZooMed series, using their TropicSun at 5500K. The Hagen series doesn't really have a comparable tube; their SunGlo at 4200K is just a bit too "warm," I actually have this with the Life-Glo in the first photo above. It doesn't look bad in that photo, but in life it is just a bit too yellow. The Tropic Sun is better, combined with either the UltraSun or Life-Glo.
You can use two Life-Glo, or two UltraSun, or one of each, but it will lack that little extra warmth. Warm light means higher red and less blue, cool is the opposite. And as red is the prime driver of photosynthesis, it is worth having a bit more of it. But you won't see a big difference among any of these tubes. But they are far superior to anything else I have tried or seen.