The Planted Tank Forum banner

Lighting a 20g Tank

1701 Views 15 Replies 4 Participants Last post by  Jdinh04
I'm new to this. I have a 20 gallon tank and I want to make sure I have the appropriate lighting. I often read about watts/gallon ratio and for most plants to grow well it needs to be above 2 watts/gallon, or even up to 3 - 4 watts per gallon.

Right now I'm using a Life-Glo 2 15W T-8 6700K bulb. To me, this would seen as not enough once the simple arithmetic is done:

15W/20G = .75w/g.

However, the market does not seem to supply a more intense bulb 18 inches long.

Any suggestions?
1 - 16 of 16 Posts
I can't really vouch for T8 bulbs. I realized early on that i would be SOL trying to light a planted tank with shop-size bulbs. There's always overdriving them...

My suggestion: search the forums/etc for a used PC fluro lighting setup. It's probably the easiest ticket into the planted tank world. Or if you're a DIY person, is a nice weekend project.
I was looking at this:

Does something like that replace my canopy? It appears the specs of the bulb is right on...
bum link. how long is your tank?
23 5/8 inches

The link was to this:
Coralife FRESHWATER 24" 65 Watt Aqualight
Deluxe Series - Single Linear Strip with 65 watt 6700K Compact Fluorescent Lamp. Great bulb for growing lush freshwater plants.

built-in ballast
on/off switch
sleek aluminum housing
(5"W x 2.1"H)
highly-polished reflector
acrylic lens cover
See less See more
I have a 20" version of that lamp which I will be retrofitting next week for more watts than the 28 that came with it. I like the coralife models. I think you would do ok with that above 24" fixture.

edit: also, it's fairly narrow, so if you don't want an open top tank you'll need to get a glass or plastic cover
get the 2x65w fixture from Coralife.
the 2X65w is a little pricey, and in keeping with what seems to be the 2 - 3 w/gallon ratio, the one 65w would seem to work.

But just so I understand, that fixture completely replaces my canopy, right?
I guess you answered my last question with your "edit"...didn't see that...
jabf - see my edit above. not really.

danepatrick's suggestions begs the question: what plants would you like to grow?
besides debris being able to easily fall into the tank, would there be any other issues with an open top?
fish "carpet surfing" aka jumping out. Arguably evaporation.
Nothing that will require a $150 lighting fixture. . . this is my first tank, just trying to keep it simple
besides debris being able to easily fall into the tank, would there be any other issues with an open top?
if you have concerns about anything getting into or out of it. e.g. kids, pets, fish jumping out.

it mounts on your tank. i'm thinking about selling mine. has been used for about 4 months now. VERY GENTLY USED. i'll ask $125 shipped. that includes the tank mounts themselves which are always sold separately. (see dr.fostersmith for $149 + shipping)
Well, I would be paying in canadian dollars, which makes it an even better deal :) However, I really can't spend that much on this at the moment. I appreciate the offer though.
I'm just using the single Coralife fixture on my 20g tank with a 8,000k bulb. It grows plants great!
1 - 16 of 16 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.