Clarification from FAQ's

[sublime]

After much debate I have finally decided I am going to try an ATS and see if I can remove my skimmer.

I know what my design approach is going to be now after reading through the entire FAQ's on this site. I was going to design a dump bucket for this but did not realize how much water needs to run over this filter. I have a 90 gallon aquarium and have 230lbs of live rock, yes that is a lot. So, I only have 60 gallons of water in the tank not including the sump/refuge which is only another 12. I plan on having a 11" wide x 10" tall screen.

Two questions:

1) Am I to understand that I need 400 gallons per hour to flow over this screen? To me that seems like a ton of flow. I was going to design a dump bucket that would dump 1/3 of gallon 3 times a minute over it but from what I have read, that is not nearly enough. 6.5 gallons per minute seems to be the minimum flow rate? This seems to me like it would be a lot of water to flow out of an 11" slotted pipe. I just need reaffirmation and clarification on this please.

2) As with anything that requires light there is always confusion. I am hearing two different things on the FAQ's. (Well reading them at least.) I should have blues and reds, 415nm-490nm for blue and 640-720nm for reds shinning as brightly as possible. However, it says not to use "actinic" lamps which seems contradictory to having the blue range of light. Also, you mention a kelvin rating of 2500-3500. I am confused on this because from what I know of photosynthesis, it is most active in the 640-720nm range and at 5500 kelvin.

So, I would like some clarification on what people have determined the best mix is and why if possible. Also, I am very tight on space and note that 12" 20w T5 bulbs are very hard to come by and there appears to only be one manufacture. Also, standard CFL bulbs at 23 watts would mean I would need 4 of them under my tank.

I have found the Colormax Coralife 20w mini compact florescent bulbs that appear to have a very good red range and even a good blue range. Would 4 of these bulbs suffice, (They are 8" long.) Or would 2 of the 50/50 bulbs and 2 of the colormax bulbs work better?

To summarize my question #2, which is confounded: A) Exactly what wavelengths of light work best and what kelvin is recommended and why? B) Will the colormax and/or 50/50 coralife 20w mini compacts work? C) Does anyone know of any 12" T5's that will work? D) Am I to understand that I need 100 watts, 50 on each side of my ATS?


Any help would be great. I just need to solve these problems and I can finalize my design.

Brandon

[Floyd R Turbo]

A few questions

Are you still planning on doing a dump-bucket design? If that's the case, are you doing a horizontal screen, or are you dumping over a vertical screen? The dump design has many different considerations. It is definitely more complicated and there really is no benefit over a constant waterfall design (in fact there are drawbacks)

You flow calc is correct. 11" wide x 35 GPH/in = 375 so 400 is fine. Is seems like a lot of flow, but you'll be surprised at how it looks when the screen is growing out, it basically just creates a sheet of water about 1/8" thick on each side.

As for the light spectrum what you're describing in terms of the "reds and blues" makes it sound like you're building an LED scrubber. Unless you really know what you're doing, I would not suggest this.

There are 2 different types of chlorophyll that you need to 'hit', and they both have peaks in red and blue like this



The K rating you want to shoot for is 2700-3500, I'm not the right person to tell you exactly why so I'll leave this to someone else. What I can tell you that based on hundreds of designs, this is the range that grows algae the best. The actinic lamps and 50/50s will not effectively grow the type of algae that you want, otherwise you would see hundreds of designs using them.

With a screen that does not match up to a readily available lamp size (like 24" or 48") then probably your best bet is to go with CFLs. 4 23W CFL sprial lamps would do perfectly, and use a good reflector (like the dome-style from HWS). You can use the CFL floodlight style too, but these are better suited for smaller scrubbers as they don't spread the light very well. The Coralife lamps would probably work, as long as the K rating is in the right range, along with a good reflector - you would need a different kind than the dome style, more of a linear reflector and the lamp would be parallel to the screen.

Another lamp you might consider is the kind that Santa Monica uses on the Nano scrubber, it's a flat quad tube so you don't lose as much light in the middle (between the lamp segments).

http://www.atlantalightbulbs.com/ecart/ ... 27.27KEIKO

There are several styles of this type of flat-tube, the "butterfly" one looks like a "W" and the lamp segments are little more spread out, so a reflector behind it would be more effective than the tight quad tube.

http://www.atlantalightbulbs.com/ecart/ ... 2P1D10102P

HTH
Bud

[SantaMonica]

4 23W CFL sprial lamps would do perfectly, and use a good reflector (like the dome-style from HWS).

Actually for a 10 X 11 screen, you will only have room for one dome reflector on each side. So I'd put a 33 watt curly-Q spiral on each side. You could try a 40 watts, but you'd need to back the bulb away a bit to stop burning.

For two bulbs on each side, you'd probably need to use the CFL spotlights.

[sublime]

Hey all,

I am sorry for my late reply and I appreciate your quick replies. Life temporarily took me away from this project.
Just as a setup to all of this, this scrubber will go above my sump under my tank with very limited space. I have a very high powered high CFM fan running 24/7 under there to help cool things and hopefully when this thing is active will help cool A LOT. (That is my goal at least.)

First to answer the dump bucket question:
No, I am not planning on the dump bucket design. I cannot fit the proper size bucket in order to achieve the flow needed.

LED:
At this time I am not going to do an LED build. I am working on a build for my nano and the arduino controller to mimic sunrise, midday, sunset and moonrise/set. I am not going to move to LED on this thing until far down the road and a lot of research can go into finding the right combination of lighting with the proper frequencies.

Light bandwidth:
Thank you for answering my question on light bandwidth. From your chart am I to understand that finding lights that have a wide peak range of 425-490nm and 600-690nm would be the optimal ranges?

The lights I think I will choose to use with a custom built plexiglass/mylar reflector:
GE 40184 - F552D/830/4P/CD - 55 Watt - 4 Pin GR10q-4 - 3000K CFL - Light Bulb
http://www.amazon.com/GE-40184-F552D-GR ... B004EZLVN2

Do you all think that two of those, one on each side about 3-4 inches away will be good keeping in mind the air circulation I have under there?

Kelvin:
Can anyone help explain why the chosen kelvin ratings are what they are? (Scientifically)


Any more help would great.
Brandon

[Chipper]

Kelvin:
Can anyone help explain why the chosen kelvin ratings are what they are? (Scientifically)


Any more help would great.
Brandon

Well, Kelvin is easier to spell than centigrade, or fairenheight, or farenheight, or farhenhieght, or darn it all, see what I mean. This is why they standardized on Kelvin.

Kelvin Color temperatures are just the temperature of a Black Body radiator that emits light in a color spectrum when it is heated to that Kelvin Temperature.

As for the rest of what you are saying, I agree with you. These correlations to Color temperature and such don't seem to line up with what is taking place here in the light spectrum.
For instance stating 3000k is the equivalent (Black Body Radiator) of light in the Orange/Yellow band. This would fall in between the two Chloryphill color peaks given above. Seems Contradictory.
Then stating a Cool Flourescent light makes more sense to me, since "White" encompasses the Whole spectrum of light. But it's color temperature is 5000K!!!

Also 3000k is the color temperature of an "incadescent Bulb", whereas 5000k (cool bluish white) is the color temperature of horizon daylight!!!
I would think this 5000k would be the best, and then I would think that 3000k would be the worst???

Sheeeesh, what do I know, I can even spell fairenheight, uh I mean farhenheight, or whatever.

[SantaMonica]

Thos bulbs lack light in the middle, but 50 watts is a lot on a 10 inch screen, so it might work. Only seen it used once, and it did not work well.

[sublime]

So, I have been doing some research on color temperature vs wave length. I finally found a chart that helped clarify the explanations I have found.



I am still a little fuzzy on exactly why a 2700-3500 kelvin bulb would work best when the key light ranges are high blues and high reds. It just does not add up to me. However, if it works, it works.

I am going to continue researching what bulbs are going to be the best to light this thing and the easiest to install.

WRT to the bulbs I posted earlier, I would think that a properly built reflector would account for any dull spots in the center. Am I am being too optimistic? Also, I think that those bulbs could lend themselves to a very slim overall design.

Any more thoughts and or help on bulb choice?

Brandon

[sublime]

I just talked to a physics professor here on campus. He assured me that if your goal is to target a wavelength, then kelvin ratings are completely unimportant and one should just look at the spectrograph of the output to determine if the light covers the desired range. This is especially true when talking about florescent lighting as the curve is not smooth but full of large peaks and long valleys. I think the fact that 2700-3500k light is working is incidental. This kelvin rating typically produces light that is dominate in the red spectrum. However, it is low in the blue spectrum. I believe is not of any benefit to specify the lighting requirements based on kelvin ratings. I believe it would be more beneficial to select a light source based on the spectrum it produces. With that said, I can understand why defaulting to a high red spectrum bulb based on the kelivn rating is common. The reality is that many bulbs people use for these scrubbers are bought at the local hardware or grocery store. These bulbs do not have a spectrograph readily available. However, if you choose a lamp with a known spectrum with peaks in the blue and red spectrum, I believe one should expect excellent results.

(This is why I initially choose the coralife colormax bulbs, they have excellent blue and red spectrum light.)

Thoughts, contradictions, comments and any other ideas are welcome and encouraged. I would like to understand this as completely as possible. Also, I am willing to perform some testing and most likely will.

Brandon

[Floyd R Turbo]

Actually I get this question quite a bit on RC and would like a definitive scientific answer. I haven't had much time to search for it on here so if it's out there, I would like a pointer to it. So far my answer has always been it is what works best so it's mainly anecdotal, and that's just not enough for some people.

I think the fact that LED scrubbers work best with 2 deep reds to 1 blue and 1 warm white are an indication of the heavy red reliance. Also I use 3000K red/bloom lamps from Avant Garden Hydroponics and they work very well, so this would seem to confirm the above.

[sublime]

I am thinking of giving up on the questions and just go with either
4 of these http://www.gladiatorlighting.com/produc ... GSTAR.html

or 2 of these http://www.gladiatorlighting.com/produc ... V-TCP.html

Which should I do? I am very very limited on space and this is hanging into my sump and the light has to be high enough and pointed down so that if the power fails, or during water changes, the sump water line doesn't touch the lamps.

Brandon