SolaTubes for reef tanks

[Danables]

I wish i still had my tubes, any new people add tubes to their tanks?

[RedEyeReef]

Just came across this and tagging along.

[reefsociety101]

Still waiting to see some pictures of a solatube tank, that is not covered in algae. Seems so promising.

[KENE]

Along for the ride!!

[RGibson]

440 cudaman-what kind of 3/4 hp pump do you have and what is the flow rate per hour and is it used with a sump ? have a good day RGibson

[SAT]

My tank's is about a year old now. There's plenty of algae... but mostly all coraline or macro varieties that my herbivores won't touch. In the picture you'll see big bunchs of Halimeda (center left), two species of Gracilaria (center right and far right), Caulerpa (center bottom), and a ball of Chaetomorpha (dead center). If I added some tangs I expect most of that would disappear in a hurry. For the record, the Cyano in my old picture is long gone.

Right now, mid-winter, the tubular skylights don't do much... little direct light goes down the tubes. To compensate, I doubled up on the VHO's in September (720W total, over a 300G tank). I expect to take it back down to 360W in March.

My corals (the few that I have) are hanging in there and growing a little. I only started feeding them recently. Most interesting is the Pterogorgia in the lower middle of the picture. It's been doing fine and grew about an inch in the last month or so. Borneman's book says Petrogorgia typically gets choked with algae and doesn't last long... contrary to this experience.

Hope that helps.

[RedEyeReef]

Tagging along

[salt lick]

SAT the tank is looking good.

I spoke to the manufacturer(distributer? cant remember) of the solatubes, and he pointed out that the light gets concentrated around the edges of the pipe (donut) and typically exits at a shallow angle (except noon) so the diffuser helps redirect the light down. I think he is only part correct, the diffuser is not a focusing lense. the best light pipe is not a cylinder but a cone. it can be a shallow cone (almost cylindrical). in the cylinder the light may bounce 6 to 20 times on the way down a 4ft section. the light would only bounce maybe 3 times in a 15degree cone, because each bounce in the cone the light is reflected into ever more parrallel (vertical) direction. I have thought of adding a 45 degree short mylar skirt (6"tall) and a clear flat acrylic lense.

[A Reef Scene]

Is there any data as to the par, wattage equivalent, and coral health and color on a running reef tank?

[Instigator]

Originally posted by salt lick

I spoke to the manufacturer(distributer? cant remember) of the solatubes, and he pointed out that the light gets concentrated around the edges of the pipe (donut) and typically exits at a shallow angle (except noon) so the diffuser helps redirect the light down. I think he is only part correct, the diffuser is not a focusing lense. the best light pipe is not a cylinder but a cone. it can be a shallow cone (almost cylindrical). in the cylinder the light may bounce 6 to 20 times on the way down a 4ft section. the light would only bounce maybe 3 times in a 15degree cone, because each bounce in the cone the light is reflected into ever more parrallel (vertical) direction.

You make a very good point. Here is a diagram:

[grim]

I think the ideal solution would be using a Fresnel lens at the output of the Solatube in order to create a more 'parallel' light output (collimated). Could possibly create some 'hot-spots' so some care is probably required in aiming and focusing the lens properly. You can probably focus a whole lot of light from multiple solatubes into a small area using multiple fresnels as a solar concentrator, and probably get alot more usable light (think many many magnifying glasses), but it would be quite an expensive experiement.

jb

[Instigator]

The lens is something I thought about myself but placing it at the top of the tube instead of the bottom. Like my previous diagram shows, the sun rays are coming in at an angle and leaving at an angle. Is it possible to put some type of lens at the top that would send sunlight more straight down? Furthermore, is there a type of lens that can gather more light at the top and send it down the tube?

[grim]

Fresnel again. The only real catch here is trying to deal with the chromatic abberation a fresnel will generate. Don't know if it would even make a difference in a solar concentrator application.

jb

[lilbuddy]

richard harker uses solar tubes on his 2000g tank..I have pics of his tank in my gallery. He also uses 65k pendants. check out my gallery for the pics. they are on the 2nd page in my gallery but here is a pic to give you an idea...
this is above the tank

[headhawg7]

Well CRAP! Why didn't you guys tell me this before I spent all that money on my HQI DE system and the electricty this thing uses, I could have paid those solatubes off in about a year or less. And possibly get a tax break!

I bet my landlord would freak if she saw something like that on the roof of my duplex. That would be tough to explain.

[lead]

lilbuddy,
Could you send me the link to your gallery.
lead

[photobarry]

Just press the "gallery" icon above his post. (It's the thing that looks like a camera.)

[SaltwaterNovice]

LilBuddy:

Are you sure Richard Harker is using Solatubes on the 2000 gallon tank?

I read his original article and I am pretty sure that he was using skylights with pendants hanging in between the skylights.

Do you have a link to a website about his tank. I haven't been able to get any additional information about that tank, excluding the recent article in the on-line reef magazine, but sure would like to.

Thanks,

Brian

[Instigator]

SaltwaterNovice, I suspected the same thing. In fact, you can see the skylight reflections in some of those pics, including a bright spot (possible pendant MH). It just doesn't look like a solartube setup to me either.

[getwet]

Wow...long post. I thought about this a very long time ago when I first saw these things...1984? Sometime in the 80's anyway. Needless to say, I'm very happy other people have laid a foundation for me to follow

A couple of comments (plus it tags me along too). First, there is virtually no red light in seawater. It gets very rapidly filtered. The yellow wavelengths are used by plants, although the exact wavelengths depend on the species and phyla (I think it's phyla that denotes red, green, and brown). Anyway, that is why you don't find grass bed communities at very deep depths, no yellow light. As for corals, many species are exposed at low tides, so perhaps a small dosing of high intensity red is good for them or even needed.

Finally, I do remember attending a talk, where someone (I think from Scripps) talked about some corals that were taken from Hawaii and placed in a rooftop container at Scripps in San Diego only to die off under direct sunlight, at what would seem like similar conditions (ie latitude etc). It turned out the problem was the light wasn't intense enough on the rooftop in San Diego vs the reef in Hawaii. I know these tubular skylights are likely better as they focus the light to a degree, but it is not surprising supplemental light may be needed for some corals.

Now...the question.... the quality of these lights is a little more important to the people on this board over the "typical user". Anyone try the e-bay tubular skylights by solar enterprises?

[dvups1]

Well, I have been following this thread for a while now and think I'l jump in. My 240 (96'24x24) is now sitting in my garage and the local Solatube contractor gave me a bid of $350 per 21" tube. So I guess I am going to go for it. I'll keep ya'll posted. Wish me luck.

[RedEyeReef]

Keep us posted. How is the relation of the tank and your roof? Meaning, is your house a rancher or is the tank located up stairs? I think I am SOL for Solar tubes, my 360 is in my basement.

[dvups1]

I'll have 8' of tube between the roof and the tank top.

[salty joe]

I recently contacted Anthony Calfo. He told me to make sure there is NOT a UV filter on the sun tube system.

[DgenR8]

Anthony Calfo is speaking at my reef club's meeting tomorrow. I'll be sure to ask him about them, as it's something I've been thinking about.