Carbon and cyano

[Eric23]

Is there a link between using activated carbon and cyanobacteria ? This could be complete nonsense but over the past few years I've noticed that when I get cyano it's usually when I'm running carbon in my reactor and it usually goes away within a few weeks of me taking the carbon out of my tank. Obviously when I have cyano I'm doing other things to lower nutrients so it may not be related but I haven't had a cyano outbreak when I'm not running Carbon on my tank ? I've also thought that maybe my water isn't as clear when I'm not running carbon therefore the bottom of my tank is not getting as much light causing less of a chance of cyano ?

 

[pandagobyguy]

I have noticed the same now that you mention it. Makes me wonder if the darbon acts as a food source or something....

 

[Chuk]

When I overdose my nopox I’ve notice cyano popping up in the sand. I back down the dosing and it goes away. This typically happens if my nitrates drop below 0.5 ppm. I haven’t noticed the same thing with activated carbon though. I’m pretty sure that it needs to be an available organic carbon source and activated carbon is coked and not organically viable anymore.

 

[Randy Holmes-Farley Verified Community Expert]

I've not heard of any direct correlation of GAC and cyano, and I'm not sure what effect could do it.

A roundabout possible explanation is similar to the explanations for dinos, that removing some trace element might deter a competitor to the cyano (such as algae). GAC binds organics and many trace metals are bound to organics. So more GAC may mean reductions of certain trace metals, and those metals might be needed by a cyano competitor (e.g., algae).

 

[Randy Holmes-Farley Verified Community Expert]

When I overdose my nopox I’ve notice cyano popping up in the sand. I back down the dosing and it goes away. This typically happens if my nitrates drop below 0.5 ppm. I haven’t noticed the same thing with activated carbon though. I’m pretty sure that it needs to be an available organic carbon source and activated carbon is coked and not organically viable anymore.

Yes, organics can promote cyano, but if anything, GAC should reduce organics and does not, by itself act as such a source.

 

[NS Mike D]

My understanding is the primary cause of cynao when dosing carbon is that it can remove NO3 faster than PO4 and that cyano can get N from other sources more effectively than algae and corals so that they still thrive on low to no NO3 with PO4 present while the others cannot. Many folks will run gfo with dosing carbon in the beginning until they can get their NO3 and PO4 balanced in their desired ranges.

 

[Cory]

would it be that carbon removes most humic substances which bind to metals , and carbon removes it. Then as the carbon ages metals build up because there no humics and bind away metals cyano was using?

 

[Randy Holmes-Farley Verified Community Expert]

would it be that carbon removes most humic substances which bind to metals , and carbon removes it. Then as the carbon ages metals build up because there no humics and bind away metals cyano was using?

I'm not sure how that impacts cyano, but certainly there are great complexities and unknowns in the bioavailability of trace metals in reef tanks.

 

[NS Mike D]

I have noticed the same now that you mention it. Makes me wonder if the darbon acts as a food source or something....

When I overdose my nopox I’ve notice cyano popping up in the sand. I back down the dosing and it goes away. This typically happens if my nitrates drop below 0.5 ppm. I haven’t noticed the same thing with activated carbon though. I’m pretty sure that it needs to be an available organic carbon source and activated carbon is coked and not organically viable anymore.

My understanding is the primary cause of cynao when dosing carbon is that it can remove NO3 faster than PO4 and that cyano can get N from other sources more effectively than algae and corals so that they still thrive on low to no NO3 with PO4 present while the others cannot. Many folks will run gfo with dosing carbon in the beginning until they can get their NO3 and PO4 balanced in their desired ranges.

did you guys mistakenly read that as carbon as in dosing rather than activated carbon like I did??? oops

 

[Eric23]

Yeah I wasn't talking about dosing carbon. I'm talking about granular activated carbon

 

[Eric23]

I've spoken to a few other people that have had similar experiences. After they pull out the granular carbon the cyanobacteria clears up much faster and when they start running granular carbon again they'll get an outbreak. There's just way too many other variables to know what's going on or if it's just coincidence

 

[rockslide123]

Maybe this is reaching. But I could imagine carbon in a bag getting dirty and becoming a nitrate source after a week or so. Not likely with a carbon reactor though.

 

[pandagobyguy]

Yeah I wasn't talking about dosing carbon. I'm talking about granular activated carbon

Me too

 

[Brien]

Personally I think there is a correlation between excessively low nutrients and Cyno. I don't think the manner those nutrients are reduced (i.e. carbon) is the cause though.

 

[Esquire805]

thats explains it

 

[Jeffcb]

This is an old post but have we figured this out yet? I am experiencing a huge cyanobacteria outbreak at the moment. It started when I added a large carbon reactor and increased light intensity. I dont see how granular carbon could cause cyano but? Its a FOWLER tank so its high nutrient but N03 is only 4. Backed lighting way down. Guess its time for Chemiclean.

 

[t5Nitro]

Interested in hearing how others keep it away as well. I have intermittent cyano flares in the tank. Certainly more prominent when the T5 bulbs are changed. Definitely seems to get worse with a new bag of chemipure elite. I dose nitrate and phosphate daily. NO3 is still 0 and phos 0.03 at baseline in the morning.

 

[Randy Holmes-Farley Verified Community Expert]

This is an old post but have we figured this out yet? I am experiencing a huge cyanobacteria outbreak at the moment. It started when I added a large carbon reactor and increased light intensity. I dont see how granular carbon could cause cyano but? Its a FOWLER tank so its high nutrient but N03 is only 4. Backed lighting way down. Guess its time for Chemiclean.

I do not believe there's a connection between using GAC and cyano growing faster.