Tip: changing bulbs = watch your nutrients!
As many of you plant keepers know, bulbs have to be replaced. How frequently they have to be replaced isn't set in stone. Its generally agreed that
NO tubes should be changed at least annually, and ODNO tubes about every 4 months.
PC bulbs are argued a lot though. Some say annually, others say 'until they burn out', and still others like myself walk the middle line. I personally think 2 years is the max you can stretch a
PC bulb.
So, just recently I changed half my bulbs out one week, and the other half 2 weeks later. Plants went crazy pearling for days. SWEET!
Then heavy duty green spot algae showed up overnight, all over my glass. Plants were fine, but I've never had spot algae so bad.
Since converting my tank to house mostly African cichlids, I've not had to dose nitrate because it's always at least 10ppm, if not pushing 15-20ppm.
So I tested
NO3 last night...and it was the purest yellow I've ever seen from that kit....not a spec of nitrate to be found. No wonder I've got algae showing up!
So of course, I dosed up
NO3, some
K, a little
PO4, and iron. I'll test at lunch to see if the plants were nitrate starved, meaning I'd need to dose
NO3 again tonight, or if they got their fill, and I corrected things.
The moral: Don't underestimate what new bulbs can do to increase nutrient uptake!