Originally Posted by standoyo

3) How long can a PL light last? I was told that PL light need to be change every 3-4months. Is this true?
False.you can use 6 to 18 months. I have what really matters is are you giving the bare minimum at start of your tank.
If you are, then when the efficiency of the bulb drops then your plants cannot grow.
Other reason to change is when colour temp of lighting changes as it ages or getting a bad bulb.

HTH


Regards

Stan