Lighting help.

[tylermakin]

What could I get away with growing with
Dual t8 24" 17w full spectrum bulbs.
38g tank. It's 18" tall.
If anyone could back me up with some calculations on this I'd apprecieate it.
I'm in the phase of doing a custom hood just trying to use a bunch of spare parts I have. The lighting with two lights is way brighter it's much improved.

 

[tylermakin]

I am also considering possibly adding 2 cfl.

 

[tylermakin]

I'm hoping to be able to get into the medium difficulty plant range.

 

[tylermakin]

After numerous hours of research and coming across a informative thread by "hoppy" I am under the impression, that my dual t8 lights are equivalent more less to his 2 bulb 48 inch hd diamond plate shop light 6500k bulb test. Hence , I should be getting around 50-55 par at gravel, and amount rising as you get closer to the water line.
If I'm understanding everything correctly, that's a lot of light! And would explain why I think it's pretty bright.

 

[tylermakin]

Difference being would be colour spectrum, being lights I have in there are 2x 8000k, surely 2x 6500k spectrum, would be better. But would the full spectrum lights I have currently work great also?

 

[Tate]

I have a dual t8 bulb also and also according to hoppys chart I should be getting medium lighting because my tank is only 12" tall

 

[tylermakin]

I think your reading it wrong there my friend

 

[tylermakin]

Depending on the quality of the reflecting your doing you may be in the high range easily. Or even too high light. If you use the graphs not the chart you may get vastly higher readings. I'm assuming that you have atleast fair reflection going on, and with only a fair amount of reflecting going on, you should be at 100 par for only 10" at gravel! Bud I'm pretty sure you have the bottom end of high lighting.

 

[tylermakin]

If you use this to judge reflector quality, I think you may find your findings much higher then you had thought.

 

[tylermakin]

T5 no it says use half value shown on chart, BUT, your using 2xt8=sameas=2xt5no so I'm thinking that the halve of the calculation being in nescessary and if you use the original "fair" line on the graph it puts you at a really high par. It's all pretty confusing but that's what I get from it.

 

[Tate]

T8 is the same as t5no?

 

[Tate]

Chart is for t5ho so I'm right chart doesn't apply to t8 bulbs