For those of you who only change your bulbs every couple of years, how has your growth and colours changed? I'll bet that for most of you the bulb spectrum has faded do much that your corals are not as bright and that your growth rates have slowed drastically. I figure my 60 gallon is worth about $5000 equip and livestock. What is it to spend $100 on new bulbs every year? That is only about 2% of your investment in maintainence, very minimal considering the maintainence costs of other expensive things like cars and homes.

Rick

I have been running mine for 2 years between changes. never had coral stop growing or algae problems with this last set but visualy they needed to be changed. Now that was with AB bulbs which are a very high end bulb, I am currewntly running SA 10K's so we will see with thoes bulbs.

Steve

I find this to be the case with my bulb swap outs too. So far, I've always replaced my bulbs before they've hit 10,000 burn hours, which, depending on the photoperiod can be as long as two years. But I've noticed, this is just subjective mind you, that when I have new bulbs, I usually think "wow that's bright" when I look at my tank, but I find myself not thinking this comment after about a year ... So that's why I use 12 months as my general rule-of-thumb ... Not so much that I've noticed coral growth stopping but that I want to have the "gee whiz" factor when I look at the tanks. :cool: :lol: