Does the dark kill cyano?

I am not completely sure about the science behind this, but when I was battling cyano, I did all the usual things, improved skimming, less nutrients, cut back on feeding...you know all the previously suggested things. And then I tried lights out for 3 days (my only corals at the time were a leather and a toadstool). Gradually lengthened lighting cycle over a 2 week period and within a week of the lights coming back on the cyano was gone....

Do I think that is why? Not really, but what I do think is that by having the lights off all of my other treatments had a chance to "catch up". Just my .02, but it worked for me and if for some reason the cyano should come back....I will do the same thing again, start with most commen suggestions and if they don't seem to be working, go with lights out.

As far as hurting the fish, they are NOT photosynthetic so lights out won't hurt them. The corals will probably also be ok. I dont think I would go more then 3 days though.

 

I hear you, thats why I only have 1 hermit in my 90, so far he has behaved himself

 

I know you're from Ohio, so you haven't experienced it so no problem. Think about this - hurricanes can blot out the sun for a few days, drop the temp (i dunno about ocean temp but maybe?) and in addition, shake up the water a lot. In short, corals will survive no lights for a few days.

 

Thanks. I really think I'm going to try the lights out and water change method. I've been doing everything to get rid of this cyano and it won't go away! My ammonia and nitrite levels are perfect, with low phosphates and my nitrates aren't that high (between 10 and 20ppm), so it's driving me nuts. I don't have any other algae, just this cyano, so it's not like my nitrates and excess nutrients are just going nuts in the tank feeding all kinds of algae and stuff. I really want to get one more small fish, but I'm waiting until I get rid of this cyano...so I'm definitely ready for it to go away! It's so annoying because everything else in the tank is just thriving.

 

No problem. That is just my personal experience. I am not an expert by any means.....but it worked for me. Be careful when you do turn the lights back on. Bring them back up to your normal schedule gradually. Even though there are hurricanes and stuff that causes the ocean to go dark, our corals in our tanks do get used to our abnormal 24/7/365 lighting scheduled.

 

My understanding from the battle I waged with Cyano is that it is BOTH able to feed off nutrients and photosynthesize. In order to kill it off, you need to first get your nutrients under control so it can't feed off of them when the lights are off. Next, kill the lights for a few days to finish it off. The corals should be fine as they are not as quick to react as the algae is to darkness.

My Tank

 

Luckily, I don't have corals, so that's helpful in this battle! Even though I'm always jealous of all the beautiful reefs on here, it does help to not have any corals when problems arise. I'm going to keep the lighting reduced and keep up with weekly water changes and see how that goes. I need to try something different!

I'll let y'all know how it goes!

 

yep, cyano can be killed without light, (most species at least, the blue green algae -cyanobacteria, which is really neither an algae or a bacteria- are very diverse, but yeah cyano in the hobby...), but with the nutrients still in the tank it is just a matter of time once you turn the lights back on. You will want to get to a long range solution.

 

I guess i'm lucky too,as I do have a tank full of corals,but there all leathers,mushrooms,zoas etc.all soft easy corals.So I think i'll give the blackout a try for 2 days(i'm off work for a few days for medical reasons)so i'll be able to monitor closely,and thanks for all the advise from everyone(it's helping me too!!)

 

edit=advice