SolaTubes for reef tanks

[JL9210]

Eddie,

Thanks for the INFO. I'll look into it.

[absolutc]

Looks as tho those tubes are coated in the same fashion as the space helmet shields the astronauts use.

Intresting.

[medrvwrx]

I just wanted to see if there was anything further on this, as I might be moving to Scottsdale sometime soon.

Tony

[biomekanic]

maybe I missed this post, but is there some way to find out if this would be an appropriate lighting choice for your area? I live in Eugene, OR. 1/2 the year it's monsoon season, the other half is pretty sunny.

[finsandcritters]

I'd sure like to see some pictures of some tanks using them. I am really considering them. I may just get some and post pictures myself.........Hmmmmm........

[dizzy]

I would just like to mention that one should be cautious when cutting holes in their roof to get light to their tank. You might do more damage to your house than you will save in energy consumption. The Waikiki Aquarium and other public institutions have been using natural sunlight for many years. This method can be very successful in summer months, but the lower lighting levels in winter still need to be supplimented with high intensity lighting like metal halide. The discovery of the later lead to Waikiki's impressive longevity success with Tridacna Gigas.

[finsandcritters]

Do you guys think there is a difference between Home Depots tubular skylight and the brand name SolaTube?

[Agu]

I've been following this thread since it's inception, and may soon be able to follow through with the idea. We're moving to the west coast of Florida. There should be enough daylight if I supplement with VHO's (actinics?). The only problem is that the house has a barrel tile roof. Can a solatube be installed on this type of roof?

Finsandcritters, the efficiency and light transfer of a ceiling light tube is a function of the reflectivity of the tube. The cheap home depot fixtures may be false economy. Do they display light transfer statistics?

Agu

[scubadude]

Originally posted by Agu
The only problem is that the house has a barrel tile roof. Can a solatube be installed on this type of roof?

Agu

Hey Agu

does your roof look like this?


I would think with some slight modifications of your roof it could be installed w/out any problems. Let me know if you need help if you DIY I could come over and help ya! I have been wanting to install some of these anyway to see how they work as I might do some myself

[finsandcritters]

Solatubes have roof flashings for all style roofs. If you look at the site they have flashing for the tiles roofs.

[kysard1]

The 21" diameter tube is the only one that comes close to having the required output. Remember that 10 watts of incandescent = 1 watt of MH.

[H20ENG]

Bump

I was thinking you could DIY these cheap with a good pane of glass, some flashing and sealant, some Mylar or spectral Al for the actual transmission tube, and some kind of lens at the bottom.

SAT, any updates?

You people with natural light got it made. I want to save on the power bill. Still use supplemental light though.

Scubadude, Your system seems to be doing well. I wonder how it'd work for me. I'm a little further north of the equator than you. 38 deg. lattitude. Lots of Hot sunny days at my house though.
Chris

[SAT]

Originally posted by H20ENG
SAT, any updates?

Chris,

The house is taking quite a bit longer than expected. At one time I thought I might be able to start up the aquarium in July... now it looks like January.

I can tell you that the tank is very pleasingly lit. The duration and intensity are quite a bit lower than in June, so I may need more supplementation for the winter months than previously estimated. I may also install the "light scoops" which help gather more light at low angles.

[H20ENG]

Thanks for the update!
I know what you mean about construction taking longer than you tought. I have been remodeling for about 3 months longer than expected
Chris

[nematode]

SAT,
tubes look nice, but I don't get why you didn't simply install one large rectangular sky light that was `~ 24 X 72 ( span the length of the three 21" tubes )and paint the walls of that "chimney area where the three 21" tubes are coming down flat white. Iwould have thought that would have brought more light down to your tank than the 3 21" solar tubes, and it would have been signficantly cheaper.
What is it that I am not getting?

[SAT]

nematode,

I considered a large skylight. Certainly that could be made to work. I chose the tubes for ease of construction and maximum light delivery. My trio of tubular skylights allow rafters to run between them, so the maximum span that has to be framed is 2'. A 6'x2' skylight requires a much more complicated structure. The labor savings is substantial... and I think you'll find a 6' traditional skylight isn't cheap to begin with.

Tubular skylight surfaces reflect around 95% of the light that hits them. I believe that's much better than you can do with paint. Most of the time the sunlight will be entering at an angle, reflecting off the walls multiple times. The difference between, say, 90% reflection and 95% reflection can be quite substantial after half a dozen bounces. Thus, I believe tubular skylights deliver more usable light than equivalent traditional skylights.

Finally, consider that my trio deliver light fairly evenly across the top of the tank. A single large skylight will tend to favor one part of the tank over another, varying with the time and season.

[H20ENG]

install one large rectangular sky light that was `~ 24 X 72

This is essentially what I was saying but using Mylar as the reflective surface rather than paint. Anyone have any reflective % #s for Mylar or spectral aluminum?

[Danables]

does anyone have a pics of there sola tubes and of there tank?

[SeanT]

This may be a dumb question, but I would still like an answer to it.

Are we positive it is just light wavelengths that make corals healthy?
What about the types of radiation the sun produces and is absobed by the corals?
I know radiation can be reflected, however, the radiation itself is degraded by the quality of the mirrors and the number of times it is reflected.
So, having said that, has anyone actually 'measured' the exit light from one of these tube and compared that with direct light from outside?

[Corpus Callosum]

oops

[Surfcaster]

Lets keep this thread going, I am thinking about going with the natural lighting (solar tubes) instead of MH.

Can we see some updated pics from you soar tube users.

[kysard1]

The thread died because it won't work unless you use huge tubes and live in the desert. The wattage comparisons are to incandescent which is 10% of Metal Halide. Won't work. Would be better off bulding a slanted mirror top and put your tank in front of a window but then you would run a chiller and still be losing on the electric bill.

[AuroraDave]

Originally posted by kysard1
The thread died because it won't work unless you use huge tubes and live in the desert. The wattage comparisons are to incandescent which is 10% of Metal Halide.

Kysard1--
Those are the stats that we have been trying to get.
Where did you get the readings and how did you measure it?

[SAT]

I think Kysard1's dismissal of the concept is a little harsh. Back in April I compared light levels by putting a photographic grey card on top of the tank, checking the level with my camera meter, and repeating the experiment outside. The camera meter showed no difference.

A camera meter uses a logorithmic scale, so it takes a substantial (say 20%) difference to register. So, let's say I got 80%.

According to Adey's charts, late April sunlight isn't much different here (SE Pennsylvania) than in many areas of the tropics. It's actually higher in May/June/July. However, in December the sun only delivers 50% and the tubes are less efficient at collecting what is delivered. The lower sun angle means less light enters the tube in the first place, it bounces more times, and it leaves the tubes at an awkward angle. Thus, I think the tubes will supply the light I need for about 6 months of the year (equinox to equinox) but will need significant supplementation during the winter.

So Kysard1 is right that these tubes aren't the whole answer. However, even with supplementation, the tubes will save a lot of electricity. I'm estimating a 60% savings on the average for myself. Plus the tubes generate a lot less waste heat and deliver a high CRI -- even after the light bounces around in the tubes for a while.

[kysard1]

The camera meter is probably not the best for this. I use a GE Ftcandle meter on the tubes and the only version which was close to a 150W MH was the 21" version with only a 6 ft tube (no turns) and a very bright SE PA (small world York here) sunny summer day. Sorry but who would want 3 or 4 close 21" holes in their roof? I think a better method could be made using a south window if you could engineer around the heat