OK, I'm looking for a light for my 20 gal. soon to be refrugium.
What am I looking for?
I want to grow algae and plants to help with nitrates.
How many watts would be sufficient?
Where can I get a good price?
Thanks.
I bought 2-23w=90w 5500k compact flo. bulbs from Home Depot for $9(2 pack)They are working great for me.I have them over a 29g refugium.I took a clamp light($5-Home Depot)) and a piece of aluminum 18"by 24"($5-Hardware store),cut a hole in the middle just big enough to screw light socket into,put the bulb splitter($2-Home Depot) on it,you simply lay one 24" side of alum. on the back ledge of refuge and bend the front edge down to the front ledge to form canopy,Keep in mind your tanks length,encase you need to leave room on the ends for hoses,ect,My 29g is 30" long so it left me 3" on each end,Its easy to remove for cleaning.I have about $20 in complete setup and my cheato is thriving.It will be kind of flimsy so be careful not knock it off,It will spring back at you,I plan on making some ends for mine,cut a pattern,leave tabs to bend over top,rivet tabs to top,and you have a closed canopy,Glass tops will still fit your tank too,I might need to put a small fan in the canopy if temps get to high,But these lights stay cool to touch.The aluminum is a perfect reflector and looks good on top of my refugium.This is a little work to build but for $20-$25 its well worth it.the thing I like most is replacement of bulbs will only cost $9 a year compared to $40 and up for other light canopy you will get from a LFS.
5-6w per gallon will grow cheato,You have a 20g,so two 60w bulbs will give you 6w per gal.You can use higher wattage bulbs,but this is the minimum I would use on a 20g.
There is always a bunch of talk about watts per gallon, but that really isn't a measure of light output. Watts is a measurement of how much power is used, not a measure of lumens.
A good example is my 90 gal tank. I have "only" 216 watts of light, that breaks down to 2.4 watts per gallon, but my coral is fine on the bottom of the tank. This is because I'm using t-5 lamps, and they put out much more light per watt then say, a standard t-12 lamp.
This is why I find it hard to determine how much light I actually need.
Accurately we can only say that you need x amount watts per gallon for type A lamp and x amount for type B lamp etc.
How about this, a 13W 6500K PC fixture.
Keep in mind that I'm not lighting the entire 20 gallons, only the center section, probably a 10 gal. area, that I'm using for live sand and algae.
