# Best parabolic reflectors for 4 T8 bulbs in a 48 x 18 in. 75 gal hood



## fishstein (Dec 12, 2005)

can anyone recommend individual high performance parabolic reflectors that will fit over 48" T8 bulbs that are thin enough to fit 4 inside of my 18 in. wide hood, or two reflectors that will each hold 2 bulbs?


----------



## bradac56 (May 9, 2007)

I'd contact http://ahsupply.com/index.html to see what they recommend.


----------



## fishstein (Dec 12, 2005)

Hi Brad,

I did ask AH Supply - they said their parabolics are really designed for the CF bulbs they sell. They really will only work well with a single T8 - two T8s side by side would be a lot wider than a single CF bulb - I need a solution that will work for at least 2 T8 bulbs at a time, or for all 4 of my T8 bulbs. I found this Coralife Aqua Mirror Reflector- 48" $34.99 which should be fine (I would need two of them), but I wonder how much better it will be than the gloss latex white paint inside my hood, which already does a pretty good job:

http://www.bigalsonline.com/BigAlsUS/ctl3684/cp18362/si1379013/cl0/coralifeaquamirrorreflector48

Anyone have any experience with this reflector?


----------



## bradac56 (May 9, 2007)

I haven't used that brand but it's just a standard square reflector.
I would bet it's not going to do much more than your latex paint.

You could buy some thin aluminum sheeting and buff the hell out of it.
Then you could bend it into any shape you want. But you'd have to
make sure it's water tight so you don't develop rust or algae on it.


----------



## furballi (Feb 2, 2007)

Definitely a custom job. A good reflector must be precisely positioned to maximize light output. I fabricate mine from mirror-finish stainless steel. You'll also need to roll the stainless steel sheet to obtain the proper parabolic curvature.


----------



## fishstein (Dec 12, 2005)

Hi furballi,

Do you know where I can pick up some mirror polish stainless steel or aluminum?

What kind of tools I would need to roll it to a good shape? If a big hassle I'll stick with my gloss white latex paint in the hood which reflects fairly well and add a straight rectangle of polished steel or aluminum on the sides front and back to angle light down into the tank. That's probably easiest.


----------



## furballi (Feb 2, 2007)

fishstein said:


> Hi furballi,
> 
> Do you know where I can pick up some mirror polish stainless steel or aluminum?
> 
> What kind of tools I would need to roll it to a good shape? If a big hassle I'll stick with my gloss white latex paint in the hood which reflects fairly well and add a straight rectangle of polished steel or aluminum on the sides front and back to angle light down into the tank. That's probably easiest.


You'll need access to a machine shop to roll the stainless sheet. I use 0.030" SS sheet. Bare Aluminum will oxidize. SS is expensive, but the final product looks great...a slim parabolic reflector on top of the tank. The SS enclosure acts as a reflector and hood. I hide the ballast on the back side of SS enclosure.


----------



## Fishdood25 (May 20, 2007)

I used Ice Caps SLR reflectors for reef tanks and you need GOOD reflectors for that kind of set up, here in FL they sell for 25 each... there the best IMO...


----------



## fishstein (Dec 12, 2005)

Hi Furballi,
Do you have a picture of your parabolic reflector setup? Did you make one large reflector rather than separate reflectors for each bulb? Sounds like it based on your description.
Would be great if you could post some photos.


----------



## fishstein (Dec 12, 2005)

Hi Fishdood,
Great suggestions - thanks very much! I just found a pic of those Ice Cap reflectors - they look great. But I saw them for T5s - will they fit T8s or do they have them for T8s?
They are just what I'm looking for.
What's the best source for them?


----------



## Fishdood25 (May 20, 2007)

Well I am new to this site and I know some message boards dont allow you to post online stores, if I am allowed please tell me and Ill post the link for you...I think the clips will fit the T8s there just alittle thicker than the T5s and the clips do flex, just try and get the ones with the plastic clips not the metal thats been coated

Can we post links to stores????anyone???? Thanks


----------



## Left C (Jun 14, 2005)

Yes, it's OK.


----------



## Fishdood25 (May 20, 2007)

OK Thanks, hello lights has them, if you were in FL I could tell ya an awsome place to get them....for the most part type saltwater supplies and T5 set ups...custom aquatics might have em....try also doc fosters and smith...and just search google !! Hope that helps alil


----------



## Fishdood25 (May 20, 2007)

http://www.customaquatic.com/customaquatic/subsubcategorypage.asp?subcatindexid=lt-t5-rf

try that there the 24.99 ones Ice Caps


----------



## furballi (Feb 2, 2007)

fishstein said:


> Hi Furballi,
> Do you have a picture of your parabolic reflector setup? Did you make one large reflector rather than separate reflectors for each bulb? Sounds like it based on your description.
> Would be great if you could post some photos.


Don't have a digital camera. The parabolic reflector is one piece (about 4' long by 1' wide). There are 1/2" flanges at each end to support the reflector on top of the aquarium. The reflector is designed to house four 4' T8s (currently using two) with two electronic ballasts mounted on the back side of the reflector.

A custom machined parabolic phenolic bracket is bolted at each end of the reflector to hold the curvature of the reflector and precisely position each T8 inside the reflector for optimum light output. I went with T8s because they are cheap to replace and provide good light output per watt. You can also paint the outside of each reflector to match the environment.


----------



## fishstein (Dec 12, 2005)

Hi furballi,

Individual appropriately shaped and spaced parabolic reflectors should push more light down into the aquarium, but your design sounds easier to construct. Did you use polished stainless steel or aluminum? 

Do you have a glass or acrylic screen just under the lights, or covering the top of the aquarium?

I agree with you about T8 bulbs. And I have a good supply for now of the best T8 bulbs I've ever seen (mine have about the same look one achieves by mixing a GE9325 CF with a 6700K CF) - nice highlighting of greens and reds. I'd like to stick with roughly the same wattage and heat output of my current bulbs and not go higher (hence the desire for reflectors to increase light a little, but not interested in more power on this tank), I just have to:

1) replace some of my end caps 
2) use some sort of acrylic or 1/8 inch glass shield to protect my end caps from moisture
3) use good parabolic reflectors for the T8s (which have been very hard to find - closest best solution I found is adapting reflectors made for T5).
4) I'd like to find out definitively if I can run a 32W and a 36W T8 off the same dual F32 ballasts as I have for a long time - so far every electronics supplier has said yes.

I'm considering the cost and time of the above versus just getting a new CF or T5 fixture/hood. With the cost of the reflectors about $20 each ($100 + shipping), glass or acrylic for 48 x 18 inch hood (no idea what it would cost now), and my supply of T8 bulbs (which others have wanted to buy), it's cheaper than buying a new dual T5 setup or two 55W CF setup, but not tons cheaper (especially if we are talking about AH Supply. However, with AH Supply bulbs, I'd have to use 2 55W CF bulbs, one on the left and one on the right of the aquarium, which won't let me mix the light well between two different bulbs (like the GE9325 + 6700K CF bulb).


----------



## furballi (Feb 2, 2007)

fishstein said:


> Hi furballi,
> 
> Individual appropriately shaped and spaced parabolic reflectors should push more light down into the aquarium, but your design sounds easier to construct. Did you use polished stainless steel or aluminum?
> 
> ...


One side of the SS is factory polished to a mirror shine. The top of the tank is covered by two pieces of glass. I set the SS reflector on top of the glass (about 2" above the water level).

My design places the T8s as close as possible to the ideal focal point of the "parabola". It's as good as one can get without using computers to trim the focal point in the X-Y-Z planes after installation.

This is a hobbly. Therefore, I can spend the time and resources to build one custom reflector. The most economical method is to get something off the shelf.


----------

