A question about my power compacts.

[marinefish]

In general, how often should i change the bulbs on my power compact? it is a 32watt 50/50 power compact in a 7 gallon bow front tank. the dept of this tank from the sand to the water surface is about 9 inches. I am also wondering what kind of corals i can keep other then the hard corals. thank you all for your input.

 

[dburr]

PC's are about once a year. I think some people and companies say they are good for 14 months.

 

[frankl15207]

My general rule of thumb is to find the maximum life set my the manufacturer and divide it in half (ie: They say one year, I change at six months). I believe that Custom Sealife rates the life on their PC bulbs at 18 months, so I would change them at 9 whether they appeared to need it or not.
Other than that, observe the tank and the inhabitants. That's always the best guide.