Light Reflector Design

[Atl300zx]

I am convinced the the reflector in my current hood is horrible.
It doesnt like the edges of my tank well and i believe my glosso
and other high light plants should be growing better than they are.

I am in the process of building my own canopy.

Here are some basic plans i put together.

Well i am gutting my current hood to pull the lights and balasts from,
i dont wanna reuse the reflectors.

I was referred to this website.

http://www.ahsupply.com/36-55w.htm

I dont particularly want to spend $60 on reflectors for the 4 65watt CF bulbs i have.

Has anyone designed one themselves and can give me some tips?

 

[TwoHobbies]

I've built all my own hoods and use white paint on the inside instead of reflectors. Three or four coates of gloss white works great.

 

[rkilling1]

This isn't going to help your problem, but that is way to much light IMO to put over a 55 gallon tank. That's effectivly over 7 WPG of light (T-12). I would shoot for something in the 2 to 3 WPG range. 2 X 65 watt is all you really need to grow almost every plant there is. And why do you have a NO bulb right in the middle of your opening?

As far as reflectors, you get what you pay for.

EDIT: Why not just run 3 T-5 HO bulbs?

 

[Atl300zx]

currently i run the 65x4 CF over the tank now and i still have issues with the plants on the sides not getting enough light. The only reason i added the NO bulb up front was so that i would get more light up front since the CF bulbs are positioned futher back on the hood. that bulb will actually turn off when i open the canopy to either feed the fish or do water changes. i plan to install a switch (like a brake pedal switch on a car).

The other reason i am using these lamps in the new hood is b/c i alredy have them and it decreases the cost of the project.

EDIT: is it just my computer or did the pictures show up like crap?

 

[hashbaz]

EDIT: is it just my computer or did the pictures show up like crap?

It's not just your computer. I believe the problem is that the pictures must be shrunk to be displayed. When a picture is shrunk, some pixels are not displayed. If the lines on the picture are only 1 pixel wide, some of the lines will be omitted.

When I click on the pictures to view them full size, they look fine. For future reference, you may want to make the lines thicker and/or start with a smaller picture.

I will sometimes run into the same problem and it drives me nuts!

edit: about canopies...

How tall is your tank/canopy? Mine is just tall enough that you cannot see the top. If this is the case, you may want to leave the top open. I nailed some narrow slats of wood to hang the lights on. This leaves the top open. The back is also open.

 

[Sidi]

For the interior of your hood I'd look into aluminum/metal tape made for ductwork as a good waterproofer with reflective qualities. Think duct tape with a thin layer of very shiny metal on the outside (you do not want to get a cut from the edge of it).

It's dirt cheap, and probably second best to mylar for increasing the reflectiveness of the canopy.

And I would agree, that's way too much lighting. Even with full CO2 injection and massive ferts...it's overkill. Are you sure it's lack of light the plants are currently facing, and not a lack of a nutrient?

 

[Atl300zx]

Are you sure it's lack of light the plants are currently facing, and not a lack of a nutrient?

The plants physically are less lit up and shaded on the sides of my tank now despite having a full length light.

 

[Purrbox]

Sounds like you are experiencing issues more with the way that light is being distributed than with the actual amount of light. Bulbs will emit more light at their center than the ends, this is just how they are constructed. A better reflector won't have much impact on distributing the light to the ends of the tank. How the bulbs are arranged in the tank will also affect how well the light is distributed from front to back.

It's advisable to use plants that aren't as much of light hogs in the areas where the lighting is going to be expectably dimmer. This helps to reduce the types of issues that you are experiencing.

Shifting the angle of the bulbs above the aquarium can also help with the front to back lighting issue. Mounting the lights so that they are mounted more towards the front and angled towards the back will help to ensure that the foreground plants are getting the light they need.

 

[Atl300zx]

Shifting the angle of the bulbs above the aquarium can also help with the front to back lighting issue. Mounting the lights so that they are mounted more towards the front and angled towards the back will help to ensure that the foreground plants are getting the light they need.

Thanks i will incoporate this aspect into the design.

 

[squawkbert]

^ sounds like a good idea.

3 more...
1) if you use AH-Supplyy reflectors (and I think you should - there's nothing better for PCs), you could make the standoffs in the center of the hood a bit longer than those on the edges. This would tip the lights ever so slightly outwward, providing a bit more at the edges at the expense of the center (where there's probably an opaque center brace anyway).

2) mount the ballasts on the outside rear surface of the canopy - this increases the odds of keeping them dry and reduces the heat load within the canopy

3) fans instead of passive heat vents - a single 12v PC fan of at least 120mm will move more air than 4 passive holes would. Having the fan at 120 or 150mm (even better) means it will be pretty well silent.

 

[Atl300zx]

The whole lighting system is completely sealed off from evaporating water. If i did put the balasts somewhere else, i would want to hide them as asethetics is important and space under my tank is at a premium (co2 bottle, canister filter, CO2 reactor, CO2 controller, etc).

As for the fans, this is my area of expertise. I went with 2 Axial outtake fans and passive intakes for a reason. First Axials fans are much more efficient pulling air than they are pushing air (hence why they are on the outtakes). Also Axial fans efficiency greatly decrease across a pressure gradiant, so as long as the sum of the area of all my intakes is equal to or larger than the sum of my outakes i will be ok. Also i put the vents on top for aesthetic purposes. i cuold also move them to the sides if desired. also the vents i am using are baffled so no light wil shine out.