Change to Metal Halides causing cyano?

[troyrb]

I just changed my 30g reef from 110 PC to a 175 10k Metal Halide. About a week after changing my lights I started getting red algae all over my tank mainly on the glass and in my skimmer. I think it is cyano algae but I'm not sure. Does this normally happen when changing lights? If so how long will it last and is there a way to get rid of it? My tank is over a year old and it had no algae before I changed the lights. I use a 5 stage RO/DI for all water added to the tank and all my levels are good except my Cal. is a little high right now.

 

[Toadally1]

I wouldn't think that would cause it. It's normal to get some additional algea growing on the glass, but not cyno. have you checked your phosphates?

 

[Anonymous]

If it is cyano it should be fairly wispy and be easy to siphon off or net. If it doesn't go away on its own, or starts to kill or endanger other stuff, you might want to consider a single dose of erythromycin. I used to believe it was a really bad idea to try this, but now on two separate occasions in two aquariums, I have gotten rid of red cyano outbreaks with no ill effects. In the second case, I deliberately did nothing to improve the water quality, etc, just to see if it would come back. Three months later and it hasn't, and that tank contains a very messy-eating triggerfish.

Before you resort to this however, make sure you try all of the conventional things like increasing water circulation, clean up or even upgrade your skimmer, etc.

 

[troyrb]

I'm pretty sure it is cryno. It is deep red and like a film covering the glass. There is a tiny bit on some of my corals and live rock also. My phosphates reads 0 and my other levels are good also. I scrap the glass every day but the next day it is covered again. I did have a coral die about a two weeks before I add the new lights. The coral was a rare type of green fuzzy mushrooms that were covering a baseball size rock, it die the day after I got it. I woke up to find brown slime all over my tank and it looked like the coral just exploded and the smell was very bad. I quickly netted out most of the slim and dead coral. I also added carbon and did a 20% water change. I didn't really consider this a calibrate since the coral died three weeks before the cryno started showing up and it all started about the same time I got the new light. Last night I was looking at the tank and noticed that the sand where the dead coral was sitting had hundreds of little tiny bubbles come up from the sand. I used my scraper to try to release the bubbles and also noticed that the sand was all hard brown in that area. Could this dead coral have been the cause of the cryno?

 

[davelin315]

I have heard that old bulbs will promote cyanobacteria, because as they age the spectrum gets distorted, but it sounds like you have new bulbs, so I don't know if it could cause the outbreak. Another possibility is that I have also heard increased temperatures will promote cyanobacteria. Did your temp increase with the addition of the MH lights over the PCs? Try NO-CYA-NO by Ecolibrium. I used it on my reef before I had SPS and it did the job well (in conjunction with siphoning and running a lot of phosphate remover).