Low light fixture for a 20 gallon tall?

[Ellenquacker72]

I'm trying to upgrade my tank from my 10 which has two 13w cfls. I only really want to keep low light plants like java fern, money wort and anubias. Right now it has a 19w T8 bulb, which I'm thinking isn't really enough. Any suggestions for upgrading my fixture semi cheaply?

 

[jcolon]

I'm not a light expert ... but a 19W T8bulb in a 20 gal is just under 1wpg ... that may be ok for the plants you listed if the bulbs are 6500K - 6700K bulb temperature ... otherwise the bulbs are only good for looking at fish. I running one 6700K 48W T8 bulb in a 75gal and my plants are holding their own ... not growing, but not dying either.

If you invest in a T5 fixture & bulb, you should have more than enough light for a 20gal ... maybe a little too much. See the link below for ideas light intensity.

PAR vs Distance, T5, T12, PC - Updated Again Charts

 

[jetajockey]

A t8 with the right spectrum as mentioned above would work for really low light stuff, however if you are going to upgrade you might as well upgrade to a better fixture so that it opens up a lot more options for you. That chart linked by jcolon is a great starting point to get an idea of where you want to be.

On some of my budget builds I just use a standard incandescent hood and use CFLs like you said are in your 10, they do a fine job and keep plants growing. I have a 29g native species tank that has 2 CFLs on a stock hood and it's heavily planted, no co2, and has been running fine for several months now.

 

[Ellenquacker72]

Before when I started the 10, I tried growing the moneywort in 15w which is 1.5w/gallon and I was not doing well. And at tank is at least 3-4 inches shorter than the 20. So ill try to find a T5 fixture, I've heard a lot about them. The bulb in is an aqua glo bulb which is supposed to have 'a really good light spectrum for growing plants' even though its at 18000k. I was planning on getting an 8000k bulb ( which is good ) if there is no other way I could get a slightly better wattage for a good price. Ive been looking around for a incandescent hood that would fit my tank, havent had much luck yet, but il keep trying. Thanks for the chart!

 

[jcolon]

Before when I started the 10, I tried growing the moneywort in 15w which is 1.5w/gallon and I was not doing well. And at tank is at least 3-4 inches shorter than the 20. So ill try to find a T5 fixture, I've heard a lot about them. The bulb in is an aqua glo bulb which is supposed to have 'a really good light spectrum for growing plants' even though its at 18000k. I was planning on getting an 8000k bulb ( which is good ) if there is no other way I could get a slightly better wattage for a good price. Ive been looking around for a incandescent hood that would fit my tank, havent had much luck yet, but il keep trying. Thanks for the chart!

No problem ... hope you have luck ... from what I understand, wattage is not an issue with T5's ... just with T8 / T12. I'm looking to upgrade to an aqueon dual T5 fixture w/ bulbs from Petsmart .. and it's for $80 which is the best price I've seen on a 48" dual T5's.