Which light promotes Algae blooms????

I have 3 MH 250's going 9 Hours and my T5 Actinics running 11 hours. Can this be causing my recent GHA Bloom. I mean Long strans of GHA are forming on my rock preventing the recent coralline growth that I see spreading. It's like a battle gowing o9n in there. HELP!!! Can this be caused by another issue? I feed every other day Brine Shrimp...Lot's of monsters in there too. I just want to stop GHA. Please help.​

 

The main reason would be b/c you have either enough No3 or Po4 or both. Test for those two elements. Another factor that can help the growth is old bulbs.


luna

 

+1 with what lunatik 69 said. How old are your bulbs?

 

Luna, I just bought new 54 W Giessmans 2 months ago and the MH 250's I don't know the age because I purchased from someone else Used. Which type lights cause the GHA the MH or the T-5's or both????

 

Hey... I'm just learning about the lights, so thanks to ya' all for your comments...

 

The T5 actinic are most likely not the culprit because the have no spectra in the orange to red range. So you need to check your NO3 and PO4 and look into replacing your MH bulbs. NO3 should be below 5 ppm and your PO4 below .05 ppm. The closer to zero the better.

 

Thanks 2in10, I was beggining to wonder if the MH would burn out and stop working or how you could tell if they are going bad. Do you judge by time only or just wait until you see an algae bloom?

 

You should do by time. I have read about 9 to 10 months. Maybe a short as 6 months. I would say after six months start looking for more algae growth, then you will have a base line. I would contact whomever you got the fixture from and see if the remember when they got the bulbs.

 

Pure actninic and blue plus lamps should have no algae growth issues. The lower the K value the more you will want to watch the bulb for spectra shift. If you can find a spectrum for each bulb you can use that to help you determine what you want to get.