Light Spectrum Question?

Question

I recently upped my 17W florescent fixture to a 20W bulb.

lumens=950

only 9000 hours!

CRI/IRC=67

Kelvin=9325

Is this good for my 29 gallon tank? The light doesnt seem any brighter than it was before course it's only 3 more watts.

Answer 1

You're working with a very good number of lumens, but the spectrum is a bit suspect...  What are you trying to dow ith the lights?  Just show off the fish?  Grow plants?  Grow coral?  9,325K (very specific number, by the way) isn't ideal for growing anything, but it will put out a nice, white light.

EDIT: High spectrum bulbs (much over 7,000K) are virtually useless for growing freshwater plants.  They are found in shallow water where the sun's spectrum is still fairly intact, unlike the deeper water coral would use, where the most intense end of the spectrum (blue) will be found.  The sun's spectrum around noon is about 6,700K (which is why they're called DAYLIGHT bulbs!), and in freshwater, that is what you want to simulate.  In marine waters, coral will receive a MUCH higher spectrum due to the depth.  Over 10,000K is perfect for such occaisons as it is VERY blue.  In freshwater, purely blue light will do nothing but grow algae.  Freshwater plants require RED light too, and 10,000K+ is devoid of such light.

I strongly suggest you read this article: http://www.americanaquariumproducts.com/...

Answer 2

If you want to grow plants, I suggest nothing less than a 15,000K spectrum. You can go with lighting like hagen powerglo bulbs which are 18,000K and 40W. They are much better if wanting to grow any kind of plant. A 9235K bulb will not do much.

Answer 3

My only question is why do you have a higher wattage bulb in a lower wattage fixture. the ballast will not push more power because you put in a higher wattage bulb. This will also decrease the lifespan of both.

Answer 4

18,000k is for for growing corals. 10,000k is the max for growing plants.