Diatoms and lighting....are they connected?

[Speakerman]

I'm wondering if wpg has anything to do with diatom growth. I assume that a low light spectrum like 5000k would grow diatoms more rapidly...but I wonder if a high wpg gallon would reduce diatom growth.

 

[roka64]

I could be wrong, but I believe it is a specific spectrum/s of light+nutrience in the water. Anyone that really knows what they are talking about, please feel free to correct me.

 

[afishyonados]

The amount of red spectrum the lights produce will determine the growth rate of the diatoms. Also, the use of city or well water that has silicates in it will encourage growth.

 

[Speakerman]

So a 10k and a 14k setup shouldn't really promote growth then...correct?

 

[afishyonados]

When the tubes are new, yes, you are correct. With time (six to eight months), they lose their original spectrum, and shift to producing too much red.

 

[Speakerman]

What is the average life of a Metal Halide bulb on a timer to run 8 hours per day.

 

[afishyonados]

Depending on the type and manufacturer of both ballast and bulb, typically 10 months to a year.