Lighting

I have a 30 gallon planted tank.

For a light source I have a sun reef 50/50 6500 trichromatic daylight & a phosphor actinic 420.

My question is, how many hours /day should I run this light to promote optimum plant growth ?

 

I would do between 8 and 12.

 

I dont believe the 420nm bulb is very efficent for plant growth. might want to change that out to another 6500k

 

You're Right

You're right. The 420 will not do much for plant growth. I got that more to show up the fish.

 

I would do around 12 hours a day to start, maybe run a 9-9 cycle. If you start to notice any algae, I would dial it back from there as needed.

 

Fluorescent Tube

As it turns out I am going to have to suffice with a plain old fluorescent tube for a week or so. The other bulb did not work. I spoke to the company who sent it & they said they would send me another. I asked about the fluorescent on my plants & they said it would be fine for awhile.