Some increasing wattage and lighting questions...

hey Mark,

I saw your other post about no one answering your lighting questions so im gonna give my .02 . (im not in any way an expert but i have been doing lots of learning here-thanks to these experts....)
1) no,you cannot get higher wattage for that length.ive seen 24" bulbs go from like 15 to 20 watts max.
2) reflectors send more light the plants way but i cannot positively say yes to your question.
3) I also cant give you a conclusive answer to this question but i have read that anwhere plants prefer 6700K or full spectrum "daylight" bulbs so maybe you can replace your bulbs with bulbs of this kelvin when it comes time to replace them?

happy to help.

I hope any others will chime in if i have made any big errors.

Hi Mark… I missed whatever previous thread. They don't all get caught, especially if you're posting at non-peak times.

thefirethief said:

1. My canopy has room for 2 x 24" bulbs, but every 24" bulb I have found is 20 watts at the max. Do higher wattage bulbs of this length exist or would I need another canopy for more bulbs...?

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You've got a bunch of options. What sort of bulbs and what sort of ballast do you have?

Bulbs are measured in eigths of an inch. A T12 has a diameter of an inch and a half, a T8 is an inch, a T5 is 5/8s. I think you guys are using these same sizes, even if you're metric. The wpg guideline is based on T12s. T8s and T5s are more efficient: you'll get about 40 to 50% more light out of the narrower bulbs. You'll also get better light out of an electric ballast as opposed to magnetic (do your lights vibrate or give steady light? The old humming fluorescents use magnetic ballasts).

An electric ballast looks like a small metal box with some wires coming out of it. You can get a larger ballast and overdrive your bulbs (just google it) and get more light out of them (it'll shorten their lifespans).

T5s are much smaller so you may be able to retrofit more of them into your hood.

Compact fluorescents (aka Power Compacts) are basically T5s bent into a U. You can get a 55w 22" CF bulb. AH Supply sells a retrofit kit for a 55 that'll fit into a 2 x 4 x 22" space. You might be able to fit two alongside each other. (I realize its not a sourcing option for you, but it'll give you an idea of what you'd need to track down for this option). That'd put you up around 2.5 wpg CF, which is probably similar to 3.5 wpg T12. 4 T5s would be similar.

thefirethief said:

2. If an aluminium reflector claims to double the output of a bulb, would I count this as doubling the wattage?

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That would depend on the reliability of the claim… double as compared to what? AH has a very high quality parabolic reflector that they claim will put an additional 61% compared to a flat reflector. Double seems like a lot… double as compared to no reflector? Nonetheless, yes a good reflector will put more light where you want it.

thefirethief said:

3. I have 2 flourescent bulbs in just now, one 18W at 7'500K and one 20W at 18'000K. Ive learned that plants ideal Kelvin Temperature is around 6'500 - 7'500 (I might be wrong there), so does that make my 18'000 pretty much obselete when it comes to considering its effect on the plants?

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The 18000 probably isn't delivering all that much useful light.

What size is your tank and what constraints do you have in your hood? I'm figuring you're about 32g. I'd figure that at 36" long… longer? shorter? How are the 2x24s configured?