This is what happens to light through bubbles. The end bit is of interest;
http://www.philiplaven.com/p8h1.html
This is what happens to light through bubbles. The end bit is of interest;
http://www.philiplaven.com/p8h1.html
As we say, the bubbles are there for moving the turf algae around (turf algae being a class that includes GHA) so I agree that the micro bubbles in the video aren't great for that but to speak to your point of light dispersion, you can get just about as bad of a sun burn on a somewhat cloudy day as on a clear one right? That is largely do to refraction.
I kind of thought that at least a glory effect would take place without refraction but I guess that, if I'm reading it right, this article shows that flashing, glitter lines and water caustics do not occur with bubbling.
Of course, setting aside increased light absorption for a moment, light disbursement away from a 2-D surface can also lower the total lumens getting to the algae. On the other hand, we have a 3-D growth environment in this design so as algal growth is more mature (longer), the total light delivered to the algae increases.
I would think that light is delivered down to the root of those strands that are successfully separated by the bubbles. Some of this light would arrive normal or perpendicular to the surface of the strands for optimal penetration of the cells and therefor good utilization. It's like pumping little flash lights down deep into the algal mass instead of straight rays of light.
How bout we send the air pump to keep the skimmer company?
i checked out the hydroponic grow websites to see what the best reflective material they recommened. 1. foylon 2. mylar 3. flat white paint. i dont know if foylon or mylar is aquarium safe or not. but there is krylon fusion flat white spray paint. krylon fusion is aquarium safe. so you could even spray it on the inside of your acrylic. and if your using a cfl with the dome/bowl reflector you could spray paint the inside of that also. cheap and easy.
has anyone ever tried to make their own air stone? take a piece of pvc pipe cap both ends. drill a hole in one cap and silicone the tubing to it or an airline adapter. then you could experiment different types of holes in it. drill different hole sizes. use a dremmel tool and make dashes ---- - - - or l l l l or / / / or whatever. maybe use two air pumps and silicone tubing in the other side too.
I remembered when I was researching a splash cover for the light on my old scrubber that glass doesn't transmit as much light as Plexiglass. Neither were great so I went without one and just cleaned the straight VHO's often. There is a tranmittance issue that has to be compensated for. It looks like for 1/4 inch of tank glass it would be something like 20% loss in light transmission. Here is a study that was done on 1/8 inch glass and acrylic.
Measured light transmission of standard soda-lime glass (typical
window/aquarium glass) and poly(methylmethacrylate) acrylic -
"Plexiglass" brand.
Wavelength (nm) % transmission
Glass acrylic
600 90 90
500 92 90
400 93 89
375 90 69
350 78 9
325 20 0
300 0 0
The thickness of the glass was 3 mm (glass thickness is metric in Canada)
The thickness of the acrylic was 1/8 " (ca 3 mm).
Borosilicate glass (pyrex) is transparent well out into the UV (at least
to 300 nm) but I don't know if it is available in sheets at a reasonable
price.
Different types or brands of "acrylic" may be different.
Kirk Marat
Dept of Chemistry
U of Manitoba
Are these measurements by a white light or was each test spectrum specific like from an LED?
150G. Reef/Mix
125G. 3 Regular Oscars/1 Jack Dempsey
75G. 20+ Africans
40G. Fish/Reef. Algae Scrubbers on ALL my SW
10G. SW Fish/Reef.
10G. SW Hospital/new fish quarantine/pod breeder tank
6 stage RO/DI system 200 GPD.
I didn't look in depth so that is all that I know. I just thought about it and did a quick search. This is probably not the BEST study in the world. I picked it because they use aquarium tank glass, whatever that meant to them at the time. Most of the ways that they could have done it, the results would have been about the same because they are measuring the amount that goes in and what percent comes out. If you search under light tranmittance(tech term) or light transmition, more of the studies want to show that their glass transmits less light so the numbers would be worse.
If someone has concerns, they can do more Googling but you can just over build if this study is backed up by others. I would think that it is in the ball park. You can see that it transmits bluer and greener light very well but as you go redder, that the tranmittance problem goes up just a little. Yellow and red is not as good but still not bad. This is what you would expect. When you look through an empty tank's glass, it looks greenish blue. The tranmittance goes down quite a bit in the ranges that you don't need anyway. I always over light my scrubbers anyway. That way, I can always back off on the hours if I need to. If you over build, this shouldn't change anything
The only reason I asked is this would be typical of a white daylight florescent type bulb. These bulbs have much less reds in them so the test would show less. I might google it later. A good test should have showed a test at say so many inches without the glass or plexi then a test with the glass and plexi at the same distance. I know in water that blue penetrates the farthest but this is based on the sunlight and it has more blue anyway. Maybe on of these light guys can chime in and give us the scoop.
150G. Reef/Mix
125G. 3 Regular Oscars/1 Jack Dempsey
75G. 20+ Africans
40G. Fish/Reef. Algae Scrubbers on ALL my SW
10G. SW Fish/Reef.
10G. SW Hospital/new fish quarantine/pod breeder tank
6 stage RO/DI system 200 GPD.
The week point of the study is that it doesn't go up to 6 1/2 or 7 hundred nm's but I'm sure that the methodology would stand up regardless of the light source. I just use this stuff as a rule of thumb anyway. If you go to a big pet store and look through a row of aquariums, what you can see through them drops to zero after 5 or 6 tanks. Like I say, I would just add 20% to my calculation as a safety factor whether I as going through glass or not.
So far I'm not liking the new style. Salt creep is horrible, I'm always cleaning the glass in front of the scrubber which when blocked inhibits the growth.
There are currently 1 users browsing this thread. (0 members and 1 guests)