DIY Reflected hoods

There are many different methods to creating a reflector in a hood... and one of the most simplest ways is actually to just paint the inside of the hood white. The principle of a reflector is simply just to reflect the light that shines upwards back down into the tank. Unfortunately, some of the latest studies have shown that a huge percentage of the reflected light is actually useless for plant growth, as due to the relective angle that it hits the water, it looses a huge amount of intensity and PAR through the top few centimeters of water. HOWEVER, there is a noted difference in the appearance of tanks with reflectors compared to non-reflected light, and often this extra reflected light is all that it needed to give that tank that extra "spunk!"

I've been looking for a "sexy" lamp to use over my Nano tank, because I need to get the CFL shining onto the water at the right angle. Most of you may already have read that a CFL is very useless in a tank if installed hotizontally, so a lamp would allow for the CFL to be mounted vertically. I eventually decided to just remake another hood using a standard hood, and came up with the following DIY on turning the entire inside of the hood into a reflector. This can obviously be done on a larger scale for bigger tanks.

What I am trying to show you, everyone rants and raves about different types of reflectors that work better than the next... but at the end of the day, regardless of what type of reflector you put in... when the reflected light hits the water surface at an angle... it looses intensity and PAR, and is very inneffective... so why not go for a cheaper solution reflection, which will give you the same look as those expensive routes.

So let's get into it.

I was planning on just siliconing some wrapping paper to the hood. You know that wrapping paper that's like an aluminium foil? (The type that us men can NEVER get things wrapped in?) Well, whilst I was at Pick 'n Pay today, I found some "contact paper" (AKA DC-Fix) that has an aluminium base to it. Basically it's a shiny piece of aluminium foil with a peel off and stick application! Here's what is needed:

Hood / Scissors / Ruler / sticky aluminium stuff / pen / and silicon



Using the ruler (or tape measure for bigger hoods) measure out the different sides of the hood, draw these out onto the back of the aluminium, and cut.

I decided to add some small pieces to the corners first:



I'm not relying on the glue behind the aluminium as I fear this may not be moisture resistant, and hence might peel off longterm. So I basically covered the entire hood in silicon, spread is out with an old credit card, and then stuck the aluminum foil to this. This also allows the benefit of being able to shift the aluminium around when you stick it, because the silicon is wet.

I would highly advice spreading the silicon around, as this will prevent bubbles occuring under the foil.

This is the finished result:



You can't see it in the pictures, but when I was finished, I put silicon in all the corners where 2 pieces of foil meet. This is to prevent any moisture from getting behind the foil

Put the light into the hood:



And voila:

 

Nice - it looks like you are using the 12 Watt Tornado light, if you find that with this mod and bulb you still have algae then you can downgrade to an 8 Watt ,1 turn less I think. If you use an e27 you can actually push the back of the bulb through the hole that you have for the b22 in and then screw secure bulb to socket outside the tank. This might also help to improve reflection since moving the light source closer to the reflection should increase the amount of light being reflected.

I'd be interested to see if the foil stays stuck .. not sure the adhesive on the foil is going to cope with heat and moisture. On my 4ft I used black ducktape to form a frame around the edges .. looked great for 3 months then the glue started streaking due to heat etc - Now it seems fused to the glass ush:

 

F fish zoom said he used silicone to avoid the above

Zoom are there before and after pics it would be interesting to see.
What's thre price for a roll of that aluminium foil?

I might give this a go!
Chrz

 

"peel off and stick application" - still concerned about the sticky stuff not loving heat and moisture and tearing (running drops) into the tank. Also not clear if the sticky stuff and silicon has a long term affect on each other.

 

You are 100% correct F-Fish... I actually though it was a genie globe. I've ordered a few genie globes from different suppliers, and they all pretty much arrived at the same time. But my impatience led me to buy a globe from Makro. So I have different types of globes lying all over the place... but I know for a fact that all the packaging says Genie, Cool Daylight. Yesterday when I put the globe in, I saw on the globe that it was in fact stamped as a tornado... so there must have been a packaging error at the warehouse/factory... not that I'm complaining, because when you compare the tornado to the genie, the tornado pushes out more Lumens per Watt.

F-Fish... you raised a very important point here. I seriously DOUBT the peel and stick application would have sufficed to hold this in place... which is why (as Brad's so correctly interpretted) I used silicon. I did peel the paper backing off, and covered everything in silicon. I had to smooth it out because obviously I didn't want the silicon to create bumps underneath. I doubt there will be any reaction between the "paper glue" and the silicon, except hopeully better adhesion.

My other concern was if this "foil" was glued to the stick side, as in 3 layers. (1) beng the foil, (2) being a double sided sticky paper, (3) being the stuff you peel off and discard. I was concerned that if this was the case, the moisure would cause the foil to delaminate from the double sided sticky paper. However, after some tearing of the paper, and fiddling around, it would appear that this was not the case.

I also need to mention that this doesn't seem to be like aluminium, but rather like a reflective plastic.

On a final note, what you don't see in the pictures is the silicon that I smeered over all the joints. Whenever I had the foil end, I put a layer of silicon over the end... this was basically to prevent any moisture from getting behind.

I like the idea you suggested with the light bulb F-Fish... I would definately look at it if the "depth" of the globe was too low... but the way it is now, is working perfectly... especially with the pegs holding the hood higher. (You know those flags we all bought for our cars, I was actually hoping to use 4 of these to lift the hood even higher, and then cover the exposed sides with plastic. However the 4 flag thingys I have were all different, and all gave different angles, and made it lok cr@ppier than the pegs.

Oh, and brads, the paper was R39.99. 1m long, 0.4m wide. So it's basically R120.00 per square meter if you want to work it out that way... can become pricy on bigger hoods.

 

I like the tray under the tank for the dribbles

 

Ssh.... that tray was a wedding present from my grandparents for our wedding!! But the fact that it needs to be POLISHED and kept "sacred" resulted in the use as you can see! HEEHEE.

For some reason, I actually believe this tray is a little more "special" than just a stainless steel tray, but I'm too scared to find out now!

 

That's a nice clean solution. I like it!
I'm thinking of just getting a 9watt desk lamp from Game for R99, or an 8watt "cabinet light" fro the same price. Either way a nice reflector would go a long way.

 

I've had a look at desk lamps, but all the ones that are "sexy" enough, or modern enough cost over R600.00 and don't hold the globe at the right angle... i.e face down. Woolworths had a STUNNING lamp... and perfect... but at R999.00 for the lamp, I decided to give it a miss.

 

Ouch, I'm just looking for something basic
The ones I've seen use the long flat CFL's. I've got an AquaH2O tank that came with one of these globes and it's doing great with mosses and marimo algae and some plants. Granted it's only a 23 litre tank, but it's enough light

 

Nice hood mod. However, I've read a bunch of tests with light meters that simply painting the canopy white yields slightly better results. Apparently because of the ripples in the aluminium...

oh, and another thing - almost all modern CFLs should NOT be used as "downlighters" - ie with the globe pointing down. The built in ballast (in the white base) gets really hot from the heat rising from the globe and will last significantly shorter... They should be setup horizontally...

Interesting - first I've heard of this, do you have a source?

thnx

 

Oh dear Dane,

You are 100% correct that paint is better... but in my opinion, messier. I wanted the easiest and fastest route.
I can see that you obviously have not been around much over the past month or so. There was a big debate on TASA as to reflectors, and CFL placing.

I've read a few articles, and conferred with a few of the more experienced members. Vis posted a link to an EXCELLENT lighting article where a guy tested different light methods, and posted his results... For the life of me I cannot find that article. (ALtho I am sure Vis will put the link up again... hint hint)

ANYWAY, to give it to you in a nutshell... If you think back to science grade 1 level, (well, standard 6 level probably)... when light enters water at an angle, it get's diffused. Test have been shown that 99.9% of the light that is REFLECTED back into your tank is USELESS for stimulating plant growth, and is purely good for increasing the lumens (for viewing pleasure) of the tank. The PAR rating and spectrum of the reflected light is lost when it hits the water surface at a reflected angle.

There has also been some tests, and the test are hugely conclusive... CFL's are 10 times more effective in the VERTICAL position, and not horizontal. If you use a PAR meter reading, and take a reading at the base of the tank- you will find that the reading on the vertical globe is up to 5 times more than when the globe is horizontal. Changing the depth of the globe also impact this sometimes up to 7 or 8 times difference.

For planted tank, the "rule of thumb" rule with regards to watts per lgallon is actually not good enough anymore. In actual fact, it is slowly been disregarded by a lot of people. The importance is PAR, Lumens per watt, and Kelvin.

I could have 40W T8 of wrong spectrum, poor PAR, and low lumens per watt, and have slow growth.
Change that to a 20W CFL/LED/T5/T2 of the correct spectrum, good PAR, and higher lumens per watt, and the tank can possibly grow twice as fast as the previous example, however with half the watts. Technology today is far overtaking.

Watts is a measure of energy needed to light up that particular globe. NOT HOW MUCH LIGHT IT EMITS!!! As lights are being designed more effeciently, less energy is required to provide high output light.

 

Gees zoom, that gives me a lot to think about. From what i've read these CFLs really suffer when used as downlighters, the heat just gets stuck in the little built in ballast and drastically reduces performance. The only thing I can think of is drilling small ventilation holes in the opposite side... (they are usually on the side that the bulb comes out). But this might break the globe..

Thanks for a very informative post btw. And your tanks are looking really great!

 

http://www.americanaquariumproducts...._Lighting.html

Here you go

 

Was interested in your DIY canopy suggestion with that reflected PnP stuff, as I am currently revamping mine, 1.8m in length. I was going to paint it white as is the general advice on the web, but I guess the reflected material might well do a better job? I will be mounting x4 54 watt T5's on it and a couple of existing T8s, probably about 30mm away with using a spacer. I wonder how the heat and moisture will effect the silicon/paper long term?

Any advice on paint and fumes, I was going to paint the outside of the canopy black? Presumably water based paint might be safer than oil based, although I have been tolled to first undercoat my existing varnished canopy, which I think will be oiled based ? I recently had a bad experience with the outside painting of our house as it killed two ancient tree ferns, before I realised what was happening. New paint can be seriously detrimental to many things including and ourselves ! Any advice on all this would be welcome.

 

You do get products on the market that you can put over the varnish in order to paint over. Not sure what it's called. My advice is go to a paint retailer and chat to someone there.

Always better if you can get non-toxic paint... otherwise leave the hood off for a few days until the paint had dried.

 

I found a metalic Spray paint over the weekend they was silver and Gold, I know how to spray paint well so for me this would work the best but it Zoom is right about the uselessness of the paint then is it worth doing at all?

 

Paint works well. White is obviously the best for reflective purpose. Remember, the reflected light won't help with the plant growth, but it does make the tank look brighter and better. So whatever you put there to reflect the light will be worth it.

 

Heavens, so I have three options.. either using Zoom's metallic paper, Lizard's spray on metallic paint or just painting with a toxic free white paint. Anybody got a coin ?

 

Sorry man, I'm fresh out of three sided coins!! hehe!!

G!