What is cyano and how do you get rid of it?

[Vegas_ReefMan]

I have some slight cyano forming in my 225 reef tank, the cyano just started. I have good aeration 3 stones in the sump, and a protein skimmer, wavy sea, and 2 tunze power heads in the tank; so aeration should not be an issue. How do I get rid of it, as I see it starting to form in the tank and it has air bubbles in the cyano and it almost looks like purple coraline but is slightly red. Thanks

 

[Vegas_ReefMan]

The only issue in the tank now is that my magnesium is at 900 which is low and calcium is at around 420-440.

 

[bertoni]

http://www.reefkeeping.com/issues/2004-05/rhf/index.php

That article covers all the water parameters, including magnesium. A supplement like Kent Tech-M or ESV would be one way to fix the magnesium issue. There's also a DIY approach, if you're interested:

http://reefkeeping.com/issues/2006-07/rhf/index.php

What is the total flow in the tank? Sometimes, more flow seems to help. In general, though, nutrients are the issue. This article discusses nitrate problems, but the ideas will help with nutrient control:

http://www.advancedaquarist.com/issues/august2003/chem.htm

A phosphate media like PhosBan or RowaPhos might be helpful, as well.

 

[Vegas_ReefMan]

I have more than 2250 gph per powerhead and I have two in the tank with a 2k gph return pump... I think it could be nitrates however the max that I ever have is at 10, which is not that high I thought. All of my other parameters are good except for magnesium which is 900 but I just got the kent mag powder and will fix that now... Please advise as to what could be the cause in the tank... Thanks

 

[Vegas_ReefMan]

I also run dual phosban reactors with phosban, and a phosban reactor with carbon in it... My phosphates are at 0...

 

[bertoni]

Well, that's plenty of flow. I expect that nutrient control will be key. Growing and harvesting a macroalga helps. How much are you pulling out of your sump, and how often?

 

[Vegas_ReefMan]

Bertoni:

The return flow is 2000 gph per hour from a RIOHf32... Is that what you meant?

 

[bertoni]

No, I mean how much macroalgae is being harvested out of the sump.

 

[Vegas_ReefMan]

Not much, I just grow red gracillaria, and brown gracillaria and ulva in floating tupperwear containers in the sump. I keep a light over it for 8 hours a day, it doesnt seem to grow too much, but the only thing in my water which is not 0 is the nitrates which are at 10. Sorry for the incorrect response... Should I add more macroalgae, or a different type? I just dont want a culerpa outbreak so I avoided that species...

 

[bertoni]

I don't understand. Do the containers have some sort of mesh to allow tank water to flow through them?

Chaetomorpha is a safer choice than Caulerpa, in my opinion, because it doesn't attach to rock.

 

[Vegas_ReefMan]

They are completely drilled with holes, I made them myself. So water is always flowing through it, I also have some chaeto... That is not the issue, what water parameters cause cyano?

 

[bertoni]

In this case, I suspect the nutrient level of the tank is allowing the cyanobacteria to grow. Often, macroalgae can outcompete cyanobacteria for nutrients, and thus eliminate it. That's worked for me. Since the macroalgae in your refugium isn't growing very well, that's not going to work for you. Some iron might help, or some of the other ideas in the article posted previously might be useful.

 

[mc-cro]

I am leaning towards excess nutrients as well. How much light do you have over your macro algea. with a 225g tank, you need to be pulling out large amounts of cheato weekly. atleast cantelope size.

 

[Vegas_ReefMan]

I only have small lights in the sump over the chaeto which are on 8 hours a day they are 120 watt fluroscents... With nitrates at 10 ppm is that high enough to cause this or is this due to the low iron levels? Thanks again

 

[Vegas_ReefMan]

What do you mean need to be pulling out tons? As i never had this problem until I recently switched to Instant Ocean Reef Crystals and started dosing strontium and calcium with Part A and Part B by Two Little Fishies... I dont know which one is responsible but all tests are within parameters except for a nitrate of 10 ppm and a magnesium of 900.