Originally Posted by Welshy
Hi I gave just been looking for 20w t8 tubes and can't seem to find any that are not by hagen glo, I have read somewhere that fluorescent tubes wattage go up in size, now what this guys saying that a 24" tube is an 18w tube and not a 20 he argues it's just a gimmick, my question is is this true? Can I put a 18w tube in my 20w ballast ?
You can't really trade wattages on a florescent fixture. Lower wattage bulbs may work for a time, but will burn out quicker. Higher wattage bulbs generally won't start up. Either way the bulb and ballast can be damaged.
Now if your fixture has a starter (looks like a capacitor), you can switch the starter to fit your bulb.
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