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eileen_plants

20w aquarium lights - will they grow?

eileen_plants
17 years ago

I just turned two 10 gallon aquariums into plant stands and am using the 20w florescent bulbs that came with the set up to supplement light. The stands are backed between two windows facing south, but in this location, they get very little natural light. Does anyone know anything about the lights used in aquarium setups and whether or not they are conducive to plant growth? I have my small succulents in one tank and AV's & ivy in the other - these are NOT terrariums, they are in individual pots and the top of the tank is covered only about 3" by the width of the light fixtures, they are not sealed.

Are these 20w bulbs "cool" or "white"?? How can I tell? I'm a complete novice to growing under lights, as I'm sure you can all tell! Thanks for any suggestions.

Comments (5)

  • shrubs_n_bulbs
    17 years ago

    How many tubes in each tank? One might be enough for the AVs, or might not, but definitely won't be enough for the succulents. Two might be enough for your succulents, you'll have to judge how they go.

    The tubes should have some cryptic writing on that will tell you exactly what they are. It will have something like "F20W" or "F20/T12" and a colour line such as "colour54", or "540". It might even say "white" or "cool white".

    A 20W T12? Probably cool white, but I know they do make them in other temperatures. Compare the tube side by side with an incandescent bulb. A warm white will look similar, a cool white will make the incandescent look quite orange. Or better yet, compare to a known cool white fluorescent. Cool white will look the same, dayling will look blue-ish, and warm white will look orange-ish.

  • eileen_plants
    Original Author
    17 years ago

    Hi shrubs, thanks so much for your help - there is one 15w(not 20w, my mistake) "aquarium lamp", as it says on the bulb. None of the above numbers were on it only the letters "Hg" inside a small circle and the number "36". Mystifying...

    I came to the same conclusion as you, that this was not going to be enough for my succulents and moved them out and back to the south window. I will give the AV's a chance, keeping a careful eye on them - I also have two spider plantlets and an ivy cutting in there, not sure whether it will be quite enough light, but if they show signs of deteriorating I will move them out. I will also try your suggestion re: the incandescent, sounds excellent...thanks again!

    Eileen

  • shrubs_n_bulbs
    17 years ago

    Yes, 15W is really not enough. Ivy will grow anywhere, almost in the dark, the spider plants should too. Keep an eye on the AVs, they might not get enough light. Or maybe they'll be healthy but never flower!

    Hg is just telling you there is mercury inside the tubes, don't know what the 36 is.

  • paintbetty
    17 years ago

    hi,

    I have a 5 gallon "hex" fish tank with a lighted hood that I'd like to convert into a terrarium. It currently has a single incandescent bulb 15w, and that fixture is built into half of the lid. I know that this will probably not be enough/the right kind of light, and wonder if I can find a more appropriate bulb the same size so it will fit into the existing fixture?

    thanks for any advice

  • shrubs_n_bulbs
    17 years ago

    You are correct, the incandescent bulb is no good for growing plants. If it has a standard screw-in fitting, get an energy saving (compact fluorescent) bulb that will screw in to the same fitting. Observe the maximum rated wattage for your hood. Hopefully there is enough room for this type of bulb, as they tend to be a bit larger than incandescents, especially the higher power ones. Ideally, get one in a "daylight" colour like 6500K, rather than the warm white (300K or 2700K) shade that is normally sold for domestic use.

    Lets see, a 5 gallon tank is what, about 1 square foot? A 15W compact fluorescent should be sufficient for low light plants like AVs or other typical terrarium plants, maybe even a little less. You would need more for high light plants.

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