Follow along with the video below to see how to install our site as a web app on your home screen.
Note: This feature may not be available in some browsers.
I believe that the can cause algae to grow if they are old enough...it's always a good idea to replace them around 1 yr or so depending on how long of a photoperiod you have...you own it to your tank to keep up with good bulbs!!
Ditto this...I also believe the PAR values can start to decrease over time as well. Good idea to keep the old ones as a backup though just in case!!
Actually, my 250 Radiums ran @ 320 watts have lost less par than my leds...... I lose about 10% in the first year, but that 10% is lost in the first few months. I have one that's running on a frag tank that is 18 months old.
Light Output of the Phoenix 14,000K DE MH Bulb Over Time by Allen Chantelois - Reefkeeping.com