bulb life and algae

[bugbdon]

hi all,
i'm starting to experience algae in my tank and it's beginning to look dirty!!!! i recently bought a used 150w sunpod, it had a pheonix 14k bulb. my question is could an old bulb be a factor in my algae? i've never had this big of a problem with it, the tank has been up since march 2008
thanks
-b

 

[EvMiBo]

I don't believe so. Infact, too much light can be a factor to algae among many other things. What kind of algae is it?

 

[seapug]

How does the bulb look? 14K Phoenix bulbs are very blue, so if it looks yellowish it might be time to replace it.

That said, old bulbs can encourage algae to grow in a tank that has nutrient issues, but the nutrients are the "true" source of the problem so I'd look into improving water quality before spending $$ on new bulbs.

 

[Capt_Cully]

As bulbs fade, the spectrum changes. Different spectra can be encouraging to certain types of algae. IME it's particularly noticeable with the green film algae on the glass. I notice that after around 9 months on an MH bulb I have to clean the glass every day or every other day. I use this as my indicator to change bulbs.

I know several people that just run bulbs until they burn out, and they have quite large, beautiful reefs. So that's not to say my way is the only way, but I think it answers your question.

EvMiBo makes a good point too. The duration and intensity of light can also encourage algae growth. Adding a MH to your system can do it if you weren't running MH's before. When changing lighting or even when I add new bulbs, I always shorten the photoperiod. This allows the corals to adjust and prevent problem algae growth that likes the intensity of the new bulbs.

Hope this helps.

 

[bugbdon]

everything you guys are saying makes sense. i proabably do have a nutrient problem, i "blow off" my live rock all the time and stuff is really clouds up the little 29gallon biocube. that being said...i need to check my nitrates and phosphates.
additionally the color of the bulb does look yellow. maybe i'll just put up with it till my 72gallon is done.....should be another few months.

here's another question....to resolve the nutrien issue how much/often can i change the water? i'm aware that too big of a change is bad so what would be a good amount to change and when can i repeat the change?

 

[Capt_Cully]

People who are trying to correct an immediate problem have changed up to 50%. I'd say for you, 10% a week is plenty. I prefer large frequent WC's to HUGE monthly changes. I've noticed increased coral growth since switching to 10% a week. So for you 2-3 gal, I bet it does wonders esp in a 29gal.

If you are trying to correct the algae growth and get nutrients down in a hurry, it wouldn't be unheard of to do a 20-25% WC.