[rollinghills]

I read the stickied thread on CFL bulbs and looks like I need a 20W bulb to achieve medium lighting in my tank. Now my tank has the 2 bulbs hood. The stupid question is will two 10w bulbs give me the same amount of light (PAR) as a 20w bulb or do I need two 20w bulbs? Thanks.

 

[Hoppy]

Two 10 watts bulbs won't give you the same PAR as one 20 watt bulb. The one bulb may not give you enough light spread to cover the whole tank, in fact even a 10 gallon tank needs to bulbs for that reason. If the bulbs are not real close together their light will not add up to too much light.