kelvin shifts from old bulbs dont cause algae problems and new lights/bulbs wont fix it, I dont know where this comes from. I've kept the same pc bulbs for years with no change in algae. buying more intense lights will make the problem worse not better. There are reef tanks with high intensity 6500k halides (where nuisance algae loves best) as primary lights and no algae problems. I guarantee you worn out flourescents (or halides) dont shift enough to be the cause of nuisance algae and even if it did it would be cancelled out by the loss of intensity of old bulbs. manual removal, phosphate removal media, maintenence practices that inhibit nuisance algae growth (if it grows well with 15% bi weekly water changes you need to do 15% weekly. if thats not doing it do 30% weekly and so forth) is whats needed. once you know you have maintainence that contains it (for example after you manually remove it and start the new practices you notice it takes 4x as long or never grows back to the problematic level it used to ) then wait for all those improved practices to take effect
I hate to go pic horing and journal writing but it gets my point across best.
I wasn't fighting any major battle but I had the expected algae growth from a newish tank and certainly annoying and nothing I could live with long term. mainly I'll shows the progression that needs to take place big problem or small problem. just big problems will take longer and more persistant upkeep.
july 08' as stated theres worse but nothing I planned on living with.I could have been less diligent and let it turn into a problem with "normal" 20% bi weekly water changes or whats suppose to be enough. on occasion I even did twice a week (up from my routine 20% weekly)
oct 08' not as bad but all my rocks are still green
keep nutrients low enough for long enough the algae WILL die off. took 5-6 months of 20% weekly water changes, granulated ferric oxide (GFO) media. as the tank matures and nutrients fall and are sustained low for extended time it CANT survive (except bryopsis, thats a different animal but it will even keep that from going total ape crap in your tank). sure I moved the sand to the sump to reduce nutrients but it doesn't matter how you do it as long as you do it. I could have done larger water changes and kept the sand in the display. there aint no quick, easy or change your light fix. its nutrients and/or phosphates plain and simple. Lights are the one variable we CANT remove (you did that anyway without success which indicates thats not the cause). all reef lighting is strong enough to make hair algae or any other kind flourish. if your bioload is high and you arent willing to reduce it you may have to do atypically big or frequent water changes to reduce nutrients. If its just phophates your lucky since GFO easily strips phosphates. if nitrates and phosphates read low or zero and algae is sky high believe the tank not the test.
at this point 12/08' nuisance algae is pretty much a thing of the past.
at present date I have stopped using GFO completely but my point is once I knew I couldn't possibly have high nutrients or phosphate issues with my routine and bioload it fixed itself it due time (5-6 months for me). If the tank happens to be 1-2yrs old and its still having these issues its a clear indicator the practices arent cunduit to whats needed for algae free tanking and permanent changes (in water changing, skimming ect whatevers going to significantly and consistantly lower nutrients and phosphates) need to be made. IF I even slip and skip a water change I can tell the difference. I cant do any less to maintain it at the algae level I'm willing to put up with and I still do a little manual removing at times if need be. if your okay with a little more algae be a little less anal. I'm sure I could do biweekly water changes without a noticable algae "problem" if didn't absolutely hate the stuff.
I did change the bulbs AFTER my algae problems were resolved.
