Help me choose an ATS configuration? LED vs T5

[kbb0118]

I've been stuggling trying to figure out the best config for my ATS. I've read all the posts about T5 and LED and I know I will go with one of those. I'm good with acrylic and will build something nice. I have a decent budget to work with for the build but am concerned about long term operating costs. I'm not worried about electricity costs so much as I am about bulb replacement costs. I have done a rapidLED kit and retro T5's before and would much prefer a fixture to retro/DIY.

Option A: double SM100, 196 watts of F24T5/HO
Includes acrylic for double height SM100 (so SM200)
4 Nova Extreme 24" lights (8 bulbs total, 4 on each side)
1 year of light bulbs
484 sq inches of screen total (242 per side)
~$420 cost to build. Annual cost of $120 for bulbs. 7 year operating costs (electricity excluded) $1,260

Pros: Tested and verified effective scrubbing configuration
Cons: Cost!! Higher flow required 770 gph.

Option B: 17 x 17 screen lit on each side with a 100W Lighthouse Blackstar CREE Led SIX BAND grow light. 200W total light.
Includes acrylic for a 18" black cube. I am thinking a cube because I am not sure of the distance required for these lights. This cube would allow me to place the LEDs between 1" and 7" away from the screen.
two 100W Lighthouse LED 6 band grow lights
578 sq inches of screen total (289 per side)
~$370 cost to build. 7 year operating cost (electricity excluded) $370

Pros: Cost! 595 gph flow, so lower. More screen sq inches. Easier acrylic build (fewer cuts).
Cons: LEDs are semi-tested and this would be "experimental". I'm not sure of the distance to place the fixture or if 100W will be too much light.

Thanks in advance!

[Floyd R Turbo]

Dude, I'm about ready to buy that LED light. Been looking for one that powerful at that price. I'd be interested to see how well it works. But for now, relying on it for filtration would be a gamble. That fixture is 7" round which means you would likely get a spot in the middle of great growth and it would drop off quickly from there. Even with a diffuser plate, you might not get even growth across the screen,m as you would have to balance distance and diffusion to get the optimal coverage and intensity. Even coverage is the problematic issue facing LEDs.

I really need a grant or something...too many things to experiment with!!!

[kbb0118]

I'm forever tinkering too. The light spread is my main concern so I called Gotham Hydropoincs and had a good conversation. The guy was interested to hear about my little experiment. They just started working with some companies on reef lights and understood some aspects of marine LED spectrums for corals vs plants so that was good. He was very knowledgable about terrestrial plant spectrums of course. He also was concerned about the spread and bleaching at that proximity. He gave me a deal on two units

90W unit: larger unit (more spread) using 1W Crees in 6 spectrums - more vegetative but still with 2 spectrums of red
http://cgi.ebay.com/NEW-2010-model-90w- ... 4159ebaa02

100W unit: smaller than the 90w so less spread, uses 2W Crees in 6 spectrums - more reds geared for flowering
http://cgi.ebay.com/2011-100W-6Band-Lig ... 3f099ba450

I'm going to slap one unit on each side of the screen and see what's what! I mentioned I would be posting my results out here.

Now to order some acrylic!

[Floyd R Turbo]

Hmmm....why bother with the 90W one that has all the UV and IR? It does have the deep red though. Costs a lot more too! I was going to call the guy too. Who was it that you talked to, do you remember? Easier to shortcut the conversation if I talk to the same guy. I've had several conversations with all kinds of different places, but I didn't talk to them...

[kbb0118]

I talked to 2 guys. Brian took my order, but the other guy (don't know is name) is who I really talked to. He's probably still there.

I'm willing to experiment with the UV and IR. He said he's done side by side tests with different plants and the results vary by plant species. Like tomatos grow better under the 90W vegetative spectrums...even though they flower. So basically I think the answer is nobody really knows what units will be best for marine algae. We just have to try it and see.

I got tired of over-analyzing LED spectrums a few weeks ago. I'm ready to buy it and try it. I would bet that both will work, but one will be just slightly better. Everything is a tradeoff. Spread, spectrum, distance, watts, blah blah. We'll see how things go.

[SantaMonica]

If you do LED's, at least use T5's on one side so you can compare.

By the way, a 2X taller SM100 is not effectively 2X the filtering, because the majority of the filtering takes place on the bottom 2" of screen when the 3D growth starts. Now if it were 2X the length, then it would be 2X the filtering.

[Floyd R Turbo]

Sean is who you spoke with. I had a great conversation with him and got a few answers that I was looking for, which may or may not have negated my need to perform an experiment, or at least I will have to modify it a little.

Basically, I found out the reason why 3000K light is better than 6000K. Red is more photosynthetically intense than blue. So if you compare the growth achieved under 3000K light to that achieved under 6000K light, you get more under the 3000K but not because of the spectrum, it's because of the intensity from a photosynthetic perspective. Similarly, when talking LED, 660nm (deep red) is significantly less intense, watt for watt, than 630mn (red) LEDs. So if you put them side by side, watt for watt, you will get significantly more growth from the red than the deep red.

I don't know how the 100W fixture will match up to the 90W fixture. We talked about that too but we talked about many things.

One thing was clear, that no one (except maybe NASA) had done a study to determine the 'perfect spectrum' or mix of spectrums for growing algae like we do, at least, not to his knowledge, which was pretty extensive (15 years in the hydroponics industry)

[vicbay]

When you say 660 reds are less intense then 630 reds. Are you refering to par measurement?

[Floyd R Turbo]

I'm not sure if it's the PAR measurement that is relevant or not. What I remember from the conversation with Sean is that they had people growing plants under only DR 660 compared to only R 630 and the 630s outperformed the 660s.

That being said, I do remember reading a study somewhere that showed that using both resulted in growth rates greater than the sum of the rates for each individually, but I don't remember if that was 630 + 660 or if it was red vs blue or something else. So I'm sure there's a "whole is greater than the sum of the parts" thing going on. What the perfect ratio is apparently is yet to be determined.

[kbb0118]

I don't know how the 100W fixture will match up to the 90W fixture. We talked about that too but we talked about many things.

One thing was clear, that no one (except maybe NASA) had done a study to determine the 'perfect spectrum' or mix of spectrums for growing algae like we do, at least, not to his knowledge, which was pretty extensive (15 years in the hydroponics industry)

That was my general conclusion after talking to Sean. There are tons of studies focusing on parts of the spectrum for Bryopsis or various green and red algae. They're hard to read, some are super old, none are geared toward what we want to do. I would bet the spectrum needs would shift based on the specific algae species you end up with on your screen. Plus robust living things like algae have a tendency to 'evolve' in new surroundings - like growing algae at 50 ft under the ocean (what they have studied and documented) vs in an ATS may cause the plant's 'perfect spectrum' to change a bit. I'm not equipped to do a proper study so I'll just try a couple fixtures out of sheer curiosity. If this doesn't work out, I'll just sell the fixtures on eBay to plant growers for close to what I got them for, empty my wallet and do T5's.

I quickly came to the conculsion that I would not be able to tell from online research which LED fixture would work better, so I'll try them both. I'd bet on the the 90W as the winner though. Just because they are super expensive...by the way there are like 2 or 3 1W IR LEDs on that 90W unit. Not enough to even talk about.



We all need grants!