Switching Incandescent to CF

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Hornpipe2

Aquarium Advice Apprentice
Joined
Oct 17, 2006
Messages
28
I bought one of those 10 gallon kits from Petsmart that came with all the equipment you need to set up a freshwater tank. My wife and I have been using it for quarantine and growing fry that we can rescue from our 55g tank, but I'd like to keep it a little bit planted too.

The current hood fits two tube-style incandescent bulbs, running at 10W each (I think).

Essentially, my biggest question is: Can I simply buy CF spiral or tube bulbs, screw them into my existing hood in place of the incandescent bulbs, and expect it to work? I'd like to replace the lighting because I want bulbs that last longer, are more suited to growing a few plants, and don't heat the tank so much. However if I'd have to change the hood, fixtures, sockets, etc. then it's not worthwhile to me.

And if it is possible to swap them, what am I looking for in a CF bulb? I understand that a bulb with full spectrum or "daylight" type is better for plant growth. What should I look for in a wattage rating (or is there a maximum wattage printed on the hood that I should follow instead?)

One final question: how does a conversion from incandescent wattage/CF wattage to NO wattage work (so I can work out an estimated gain in light output)?

Any help you can give would be much appreciated!
 
Hornpipe2 said:
I bought one of those 10 gallon kits from Petsmart that came with all the equipment you need to set up a freshwater tank. My wife and I have been using it for quarantine and growing fry that we can rescue from our 55g tank, but I'd like to keep it a little bit planted too.

The current hood fits two tube-style incandescent bulbs, running at 10W each (I think).

Essentially, my biggest question is: Can I simply buy CF spiral or tube bulbs, screw them into my existing hood in place of the incandescent bulbs, and expect it to work? I'd like to replace the lighting because I want bulbs that last longer, are more suited to growing a few plants, and don't heat the tank so much. However if I'd have to change the hood, fixtures, sockets, etc. then it's not worthwhile to me.

And if it is possible to swap them, what am I looking for in a CF bulb? I understand that a bulb with full spectrum or "daylight" type is better for plant growth. What should I look for in a wattage rating (or is there a maximum wattage printed on the hood that I should follow instead?)

One final question: how does a conversion from incandescent wattage/CF wattage to NO wattage work (so I can work out an estimated gain in light output)?

Any help you can give would be much appreciated!

Lots of questions here. I'll give you the simple answer. No you cannot replace the NO bulbs with CF ones. Those tube lights are meant for 10watts/foot, and the only way to get more light out of them is to overdrive the ballasts.

I use a 6700k bulb on my tank, many use these and 10000k bulbs as well. Actinic does not provide much if any light for plants, but does make them and fish look better IMO. 50/50 bulbs are nice in some setups where you don't want the full amount of light for your tank due to CO2/fert issues. You probably won't have that problem however.

So basically, unless you replace the light fixture, or overdrive the ballasts, you pretty much don't have any options. I have several "tweaks" that will increase the amount of usable light for the plants without actually changing out anything which I can post if you want.

Oh and 1.3X I believe is the going number from CF--->NO watts per gallon rating. So 1watt of CF lighting is equal to 1.3wpg. Please note that on small tanks such as 10gallons and smaller the amount of watts required per gallon is higher than in your 55gallon tank for instance. That is to say that the same plants that only require X wpg in your 55 gallon tank will require X+Y wpg in order to grow well in the 10gallon.

HTH
 
Oops, I guess I'm getting my types mixed up.

I don't have NO flourescents now. I just have those skinny incandescent filament bulbs that I'm considering replacing with the CF screw-in kind. Sorry for the confusion!
 
Wait, I thought you have the long tube bulbs (like a department store or probably your work uses)?
 
My existing bulbs look kinda like the ones on the left-hand side of this picture.
product4.jpg


Or like this, only probably longer.
B150.jpg
 
Ah, then yes you can replace them with CF bulbs! These should produce less heat per watt than the incadescents. I would look at the current wattage of the bulbs that are in the hood and try to match a similar wattage rating for the CF bulbs. Maybe someone else with experience with this same type of hood can comment on a replacement options.
 
go to walmart and look for the CF bulbs in the fish area. they have a higher k rating that u will need and alos work great. no modifications needed. u can get 10-15-20-25 watt whatever u want. 30 watts over that tank of the screw in CF should give u medium low light and u can support a variety of plants. crypts anubias, ferns moss... there are more but i am bad at naming low light plants lol. u can usually buy these bulbs at your local fish stores aswell but they are a bit more pricey.
 
I didn't find my Screw-In CFL's in the Fish Department- I found em over with the other light bulbs. They are manufactored by "Lights of America" and say on the package the color temperature- I think it's 6400K.

Lights of America also makes higher wattage bulbs that are different colors and probably not good for plants, so check for the color temperature. I think they went up to 25 or 30 watts before they changed color temp.
 
To add to what everyone else has said. Yes you can replace the Incadescent bulbs with CF bulbs. The incadescent bulbs are actually 50watts, but they use most of that energy to create heat and very little light. As such incadescents are nearly useless to plants, so comparing the new CF bulbs to them is rather pointless. You can use 10-25 watt bulbs in that fixture safely (possibly higher, but you'd need to double check that the bulbs will actually fit) and can get some rather good light over the tank.

As far as figuring out the comparison of CF to NO lights goes, it's a bit tricky with the screw in CF. There's some loss of power since they're self ballasted and additional loss due to restrike. Then there's the issue with small tanks requiring more light to reach the various lighting levels. You're best be is to get input from others as to the types of plants they're able to grow with a particular set of bulbs over a 10 gallon and go from there, or to play with it yourself seeing which plants do well and which ones don't. From this you will be able to get a good idea of the actually lighting level that you have achieved.

Some things to keep in mind as you select your new bulbs. The U-shaped bulbs are more efficient than the spiral bulbs. The reason is the you will loose a lot more of the light to restrike (light lost due to hitting the bulb) with the spiral bulbs. A pair of the 10 watts is a really good place to start and will allow you to try a variety of the hardy beginner plants. The higher wattage bulbs could probably push the lighting up into medium, maybe even medium high light. This would open up your plant options but also require more fertilization and possibly CO2. Just aim for daylight bulbs (between 5000K and 10000K) and the spectrum should be fine for the plants and look good to you.
 
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