400 gallon project

[untamed]

Originally Posted by JDigital

So what are you thinking Brad... every 9 months for replacement bulbs now? maybe even 6?

What is your lighting schedule like?

Originally Posted by fkshiu

Brad and the other purchasers of the PAR meter will be keeping a close eye on our PAR levels over time to determine how quickly PAR levels drop off. It will probably vary somewhat depending on bulb and ballast combos.

I sure hope I don't need to replace those bulbs every 6 months...they cost $600 a set! Based on this past experience, I'm guessing that my current situation will result in new bulbs every 10 months. The PAR meter will help, but I'll also be a bit wiser than before about recognizing the symptoms.

My lighting cycle is such that the bulbs are running 9 hrs per day. Just this moment, I realize that I increased the lighting hours/day in the 2nd year of the tank. That might explain why my first bulbs seem to make it to 1 year without problem, while this set didn't...I ran this set 11% longer.