Cyano only in the sump

[Makara23]

I have cyano contained only in the sump, none in the display. It's not a lot, but it's there and seems to only grown on macro algae. Do I need to be concerned? Will it eventually migrate to the display?

I think it only grows in the sump is because the turnover rate and flow is very low, almost stagnant water in some areas of the sump. I will put a powerhead in this area.

Tank is only 7 months old, phosphate is about 0.05ppm and nitrate about 10ppm.

 

[taricha]

This is one common mechanism of growing Cyano. Stressed macroalgae make a very good environment for growing cyano. This is probably due to nutrients released under stress or damage.
Sump macros are a frequent good place for my system to grow cyano too.
@Dan_P do we think high light/ low nutrients is enough of a stress to cause this, or does it need to be something else?

 

[Dan_P]

This is one common mechanism of growing Cyano. Stressed macroalgae make a very good environment for growing cyano. This is probably due to nutrients released under stress or damage.
Sump macros are a frequent good place for my system to grow cyano too.
@Dan_P do we think high light/ low nutrients is enough of a stress to cause this, or does it need to be something else?

Yes, too much light for a given amount of inorganic nitrogen and trace elements, e.g., iron, manganese, molybdenum, will stress algae. They can’t utilize all the light energy and suffer from a build up of reactive oxygen species. In response they make yellow pigments to shade themselves and dump organic carbon that can’t be used because growth has slowed for want of nitrogen. Add more light and the algae can die. Whether cyanobacteria use what leaks from the stressed algae directly or it derives something beneficial from heterotrophic bacteria living on the stressed algae exudate is something to ponder.

I think the above explanation also covers the reason algae or turf algae reactors become slime reactors. Cyanobacteria seem well adapted to deal with high intensity light and low nitrogen. Maybe this is evidence for one of the hobby’s Big Foot sightings: nitrogen fixation.

 

[Spartan76]

...too much light for a given amount of inorganic nitrogen and trace elements, e.g., iron, manganese, molybdenum, will stress algae. They can’t utilize all the light energy and suffer from a build up of reactive oxygen species. In response they make yellow pigments to shade themselves and dump organic carbon that can’t be used because growth has slowed for want of nitrogen.

I have observed cyano covering my chaeto and caulerpa in my sump and am trying to modulate the light correctly. I think too low light does the same thing ?? So, what is your source for this information? Moreover does anyone know ideal lighting in terms of par and duration?

 

[Makara23]

This is one common mechanism of growing Cyano. Stressed macroalgae make a very good environment for growing cyano. This is probably due to nutrients released under stress or damage.
Sump macros are a frequent good place for my system to grow cyano too.
@Dan_P do we think high light/ low nutrients is enough of a stress to cause this, or does it need to be something else?

Yes, too much light for a given amount of inorganic nitrogen and trace elements, e.g., iron, manganese, molybdenum, will stress algae. They can’t utilize all the light energy and suffer from a build up of reactive oxygen species. In response they make yellow pigments to shade themselves and dump organic carbon that can’t be used because growth has slowed for want of nitrogen. Add more light and the algae can die. Whether cyanobacteria use what leaks from the stressed algae directly or it derives something beneficial from heterotrophic bacteria living on the stressed algae exudate is something to ponder.

I think the above explanation also covers the reason algae or turf algae reactors become slime reactors. Cyanobacteria seem well adapted to deal with high intensity light and low nitrogen. Maybe this is evidence for one of the hobby’s Big Foot sightings: nitrogen fixation.

Ok so to sum it up, it could be one or a combination of all these: my nutrient and trace elements are too low, lights too high, low flow, causing unhealthy macroalgae where cyano takes over?

I will dose more chaetogrow, switch to 12h sump lighting (currently on 24/7), and place a powerhead down there. I'll report back in a few weeks

 

[Dan_P]

Ok so to sum it up, it could be one or a combination of all these: my nutrient and trace elements are too low, lights too high, low flow, causing unhealthy macroalgae where cyano takes over?

I will dose more chaetogrow, switch to 12h sump lighting (currently on 24/7), and place a powerhead down there. I'll report back in a few weeks

That is what I would do.

I found vigorous flow in my Ulva pond essential for growing clean algae, though it can still harbor some cyanobacteria on the surface. My Ulva clumps make several loops around the pond every minute. The output from the small powerhead is strong enough to tear off any weak parts of the frond.