is this lfs advice correct?

[u2_Crazy]

I know this is probably best in the planted forum but I'll ask here anyways. I have a standard 20W Flourescent bulb on my 29ga tank. Will changing the bulb to an 18,000K Aqua bulb improve the chances for my plants? I realize it's under 1Wpg but I can't afford a new ballast right now so the lfs said I could grow Hornwort and Java Fern, but my Hornwort is 5 days old now and looking very droopy. the lfs said the new bulb will make everything better, do you agree?

 

[jonnyb1425]

You could always use one of the specialty plant bulbs.

 

[Zezmo]

Changing the "color" of the light without increasing wattage is unlikely to have even a noticable effect.... er except on your pocket book after spending the bucks on some specialty bulb.

 

[jsoong]

Agree with Zezmo. You really need more light. However, if the bulb is very old (say a couple years) a new bulb will help - old bulbs get dimmier with age, some say up to 50%.

I wouldn't bother with fancy bulbs in a low light setup .... you could try a daylight full spectrum bulb which is relatively cheap, but I doubt you'll notice too much difference.

One way to get more light to the hornwort is to let them float at the surface. Water absorbs a lot of light so if you have floating plants, you own't need as much light.

 

[workfortheman]

18000K is too high for plants. Useful light is between 6700K and 10000K.

I doubt hornwort will survive under 20watts of normal output fluorescents. Anubias probably would, and java moss would. Possibly some cryptocorynes.

 

[u2_Crazy]

I appreciate the advise, and I'm not trying to argue, but here is a pic of my hornworts thriving under the current 17W bulb, and here is the product info for the bulb I am speaking about.

Light:
http://www.hagen.com/canada/english/aquatic/product.cfm?CAT=1&SUBCAT=112&PROD_ID=01015840010101

My Hornworts:
http://www.aquariumadvice.com/viewtopic.php?t=67481

So, what I was asking, would the bulb (link above) be better for my plants than my current bulb (which is working but is limiting me). I just want to have a nicely planted tank without a new light ballast (which I can't afford)

Thanks

 

[Guest]

Java Fern, Crypts, anubis.. sometimes anacharis will do well in low wattage.

 

[malkore]

Changing the "color" of the light without increasing wattage is unlikely to have even a noticable effect.... er except on your pocket book after spending the bucks on some specialty bulb.

Kudos for being the first to answer with the right response.

18000K is gonna grow plants. Kelvin ONLY tells us what color the visible light is...it doesn't really describe the spectral output.

I've used a 14000k tube with excellent peaks in the red and blue spectrum. However it was still just 20watts, and thus not enough for 99% of plants...same situation as you. So changing bulbs might give you a more pleasing color inside the tank, but the plants won't know the difference. Its very much about quantity of light, first and foremost...then quality of light.

As ashley states, java ferns, anubis bartari v. nana, and many cryptocoryne species would be just fine under that level of lighting.

 

[hashbaz]

I bought those aqua-glo 18000K hoping that "the perfect spectrum" would help cheet the wpg rule - but they don't.

These lights are a little purplish and will bring out the blue and red colors in your tank (these are great for red plants - see avatar). To the human eye they seem a little dimmer than the yellow/white bulbs.

I also found these "specialty" bulbs to be cheeper than most daylight bulbs.

 

[Guest]

you can also go to Home Depot (i love that store) and they sell the aquarium full spectrum lights for a LOT cheaper.