CFL Bulb: the Cheap Upgrade to the Aquarium Hood Light




CFLs(Compact Flourescent Lightbulbs) are getting cheaper and better in every way. But meanwhile flourescent lightbulbs for aquariums at my local fish store costed around 12 bucks and seem to be getting more expensive. It diddn't help that my aquarium hood light's circuitry was all rusted and broken and bulbs would burn out on a weekly basis because of it.  Finally I was fed up with it all and decided to do something about it.

At first I found the instructables on how to make an led light. I thought I would do that but when I went to Fry's Electronics I found out that it would be like 40 dollars to by all the led's I needed. I couldv'e bought them online but being my impacient self, I diddnt. Plus I diddn't like all the tedious soldering that went into everything.

Finally I came up with this: The Compact Flourescent Aquarium Hood Light
some benefiets are:
-No soldering!( YAY)
-Easy to aquire materials
-Brighter aquarium
-Cheaper to replace bulb
-Every time you replace the bulb it also replaces all the circuitry so it'll last a long time

DISCLAIMER: I am not responsible for anything that happens to anyone that  does this instructable.  Its pretty straight forward and easy but we are dealing with 120 volts AC so its possible for someone get hurt or for something to catch on fire.

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Step 1: Things You Need

 Here are the materials you need:
-Aquarium hood light
-CFL Bulb
-Not needed desk lamp
-wire connectors- rated 120 volts (I found these in the old circuitry of aquarium hood light)
-Sheet metal or Aluminum Foil (I used sheet metal but aluminum foil would probably work just as well)

-Hot glue gun 
-Screw driver (for taking out the circuitry of hood light)

Step 2: Take Everything Out of the Hood Light

This is pretty self explanatory, but make sure you save the wire connectors from it.  After you're done, you will have the case made.   Sorry no pics

Step 3: Take the Light Fixture Out of the Desk Lamp

For this step, take the desk lamp and somehow take the actual fixture out.  For mine, I had to unscrew a nut off the back.  Now trim the cord with some scissors so it's about 3-4 inches long and strip the rubber back so bare wire is showing. It should look like the pic below except without the sheet metal and other stuff around it.

Step 4: Glue in Sheet Metal/aluminum Foil

 Glue the sheet metal or aluminum foil near the middle of the hood light case.  If you use sheet metal, then I would recommend that you use a book to crease the metal to fit it exactly.

Step 5: Glue the Light Fixture Into the Hood Light

 Here you have to use hot glue to glue the light fixture in. Make sure it's the correct distance away from the sheet metal so that the light reflects off of it.  Also, use something to space it up so that when you insert the light , it isn't touching the sheet metal or the aquarium itself.  I used a scrap piece of metal for it.

Step 6: Put Connectors on the Wires

 Here you just want to connect the wires from the light fixture to the power cord of of the aquarium hood light.

Step 7: Test It

 Now you just screw in the cfl bulb and plug 'er in.  If you did everything right then it should light up.
Hooray, you have just upgraded your aquarium light. 
If you have any questions just comment

ps. sorry for my shortage on pics

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    21 Discussions


    7 years ago on Introduction

    Great idea... but the bulbs meant for aquarium use need to be used they provide parts of the spectrum that fish and plants need, (never use a cfl for saltwater the coral will suffer). i've been breeding fish for a while and have tried many different types of lights and in the long run the flourescent tubes are better for your aquarium.

    4 replies

    Reply 7 years ago on Introduction

    In a small still water aquarium anything does a good job: Incandescents lamps, CFL, leds, indirect sunlight, whatever.


    Reply 4 years ago

    Also not true. The light temperature, the wattage, pars and purs all make a huge difference. Using any old bulb can add excess or not enough light. Which can lead to big problems in your tank, especially ths dreaded bba.


    Reply 3 years ago

    It all depends on bio load, filtration type and how much, frequency of water changes and quality of water being used for said water changes. Though I do agree that too much light will make it hard to keep algea under control.


    Reply 4 years ago

    You certainly can use cfls for saltwater. They are called Sho bulbs. They are available in 10000 kelvins or more which is plenty of light temp for corals. They also deliver more useable pars and purs and use less energy than metal halides and flourescents.


    9 years ago on Introduction

    .  Great job
    .  As lemonie points out, fluorescent tubes for aquaria output a different color mix than CFLs (or maybe I should say that I haven't seen any CFLs labeled for aquarium use). Any live plants may suffer (but the increased overall light level may make up for it).

    3 replies

    Reply 8 years ago on Introduction

    they make full spectrum grow CFLs, and hopefully CFLs labeled for aquarium use never happen, because of the pricepoint of things. currently using 2 CFLs on my 10 gal glofish aquarium, two party bulbs from Wal Mart, one accentic (sp?) and one UV/blacklight.


    Reply 9 years ago on Introduction

    These guys have them for aquarium use...

    They do make them, but they cost more than standard CFL bulbs. The color output isn't really as big of a deal as the bulb makers would have you believe.

    It is more critical when using fluorescent bulbs with reptiles or with corals. These applications do need full spectrum.   


    9 years ago on Introduction

    The aquarium tubes are expensive because they output at higher colour-temperatures than other fluorescent tubes, this will have some effect upon the tank & things living in it.


    5 replies

    Reply 9 years ago on Introduction

    More then enough information to conclude that some CFLs are just as good as aquarium flors lights...


    9 years ago on Introduction

    One thing about these CFLs as well is that when they get dimmer from wear, when you replace them you get all new driver electronics as well. They dont go dim as fast as tubes either.


    9 years ago on Introduction

    You know, I think I may do this, I'm getting sick of the fluo. tube in ours (so inefficient and takes up room in the top where I store the food & cleaning stuff), AND you can buy proper light bulbs for aquariums in CFL form, so, yeah, great idea... :)

    Painting the inside of the hood white is really simple and makes the light output even better then the sheet metal. Thats what Ive seen done and done myself.


    9 years ago on Introduction

    Actually, the Home Depot and Lowes sell CFL that go up to 6500K which  would be ideal for an aquarium.