Lighting Comparison

[Floyd R Turbo]

Between this site and RS, I have looked at dozens and dozens of scrubber designs, and in designing my own (for customers), I have one main question. Is there any way to compare one type of lighting system to another when it comes to the strength of your scrubber?

What I'm referring to, mainly, is the scrubber efficiency when using T5HO lamps versus CFLs. As far as lumen output per watt used, that can be measured or is provided generally by the manufacturer of the lamp.

What really makes a difference, in my opinion, is the fact that most CFLs are concentrated light sources, and regardless of what kind of reflector you use, you end up with spot concentrated algae growth. I have seen this in many scrubber examples. It works and it's cheap, but for me, price is not the issue - efficiency is.

What I have worked on designing is a system (Santa Monica 100 knock-off) that uses 2 sets of 2 horizontal 24" T5 HO lamps (24W each) and Sunlight Supply TEK II Retrofit Reflectors on a 20" wide, 6" high screen (that is the actual lit are of the screen - I have subtracted out the area of the screen that is in the pipe, the area shielded from the light, and the area underwater at the bottom). To me, it seems like this arrangement would produce an much, much more efficient filter than a system of similar screen size (as far as square inches goes) but instead using the same lumen output equivalent of CFLs. So is it possible that you can actually use less total T5HO lamp wattage and achieve the same results than if you used the recommended 1 WPG CFL wattage?

What I'm worried about is if I design my filters, and they end up being too powerful because I'm using the HO lamps and top-end reflectors. The TEK IIs are supposedly extremely efficient compared to other similar reflectors (they have something like 28 bends instead of 16)

[Eclip]

Its really about PAR per unit area for algae. That is where the efficiency comes from. Since algae has many chemical components that convert different parts of the spectrum into food for the algae it is hard to measure its PAR. it seams red heavy works well as found by the LED scrubbers etc good work guys btw.

I don't think there can be too much scrubbing power as you suggest but if their is not enough nutrients as it has scrubbed them out then it will slow growth. The user can then reduce lighting in that case if it slows right down much the same way there cant be too good a water parameters. The higher lumans per watt the more efficient and their elongated structure on T5HO's compared to CFL is why they are much better. Generally higher lumans = more PAR = better growing potential.

[SantaMonica]

Definately T5 is best, due to even light distribution across the screen.

[Floyd R Turbo]

Can you clarify for me what PAR is? Are you talking about the reflector (parabolic aluminized reflector)?

I guess I never thought about backing down the light cycle to compensate for too much light. In that respect, I guess it would be wise to over-light a screen, because if you under-light it, you're in a world of hurt.

Also, the lamps I am planning on using are Plantmax 3000K Red/Bloom grow light from Avant Garde'n http://www.aghydroponics.com/T5-2Ft-Gro ... l24830.htm - Can't beat the price - 8 24" lamps for $32 shipped. I got mine in 2 days.

I just happened across that site when searching for the 'perfect lamp'. If what you say about how well red spectrum LED works, this should be pretty good.

[SantaMonica]

3000k is fine. The more light you have, the more flow you need.

[Eclip]

PAR as in photosynthetic active radiation what the plant uses to actually grow