Something causing Cyano

[jmp21677]

I have a redsea 170 and I'm recently having problems with Cyano. I have brand new bulbs in a ati powermodule. Good flow with an mp10. Not sure if my settings on my fixture could be causing it? Right now the lights about 10" off the water and at about 50%

 

[saltyfilmfolks]

Age of the tank? Parameters? anything you are dosing or feeding?

 

[jmp21677]

Year old
Not dosing anything. Little bit of alk to keep levels up. Battle to keep it above 7
Alk 7.5
Calc 405
Mag 1200

 

[saltyfilmfolks]

Year old
Not dosing anything. Little bit of alk to keep levels up. Battle to keep it above 7
Alk 7.5
Calc 405
Mag 1200

hmm. no aminos or carbon dosing? Hows nitrates and phosphates.

 

[wattson]

taggin,,have same issue,,tried peroxide treatment ,,skimmed heavy,,water changes,and do not dose anyhting but the big 3 and Iodide..cyano still comes back

 

[saltyfilmfolks]

taggin,,have same issue,,tried peroxide treatment ,,skimmed heavy,,water changes,and do not dose anything but the big 3 and Iodide..cyano still comes back

For you and the OP. steady PH above 8?

 

[wattson]

yep it is and I micro bubble mostly every night for 8 hours plus with a refugium on line too,,so PH is atleast 8.0

 

[120reefkeeper]

hmm. no aminos or carbon dosing? Hows nitrates and phosphates.

I'd also like to know where the nitrate and phosphates are at.

 

[mcarroll]

Is it a heavy bio-load?

What do you feed and how do you do it?

I would say an mp10 is likely to be minimal flow for a 24 x 20 x 20" tank – they're pretty strong within a foot, and adequate out to about 18". Past that....?

Did the new bulbs seem to bring it on?

The bottom line is that there's a nutrient reservoir – P, for example – that the cyano are outcompeting everything else for.

Too little nitrogen (indicated by ultra-low or zero nitrates) starves out everything else, but cyano can fix N2 when other sources have dried up.

As bacteria, I wouldn't be surprised if they can outcompete everything else for P as well, so zero NO3 and zero PO4 simply means that they're using up the next-most limiting nutrient. I think I've seen Randy suggest that this is likely Fe....but tick off the whole Extended Redfield ratio list for possibilities.

Of course every rule of thumb like Redfield has numerous exceptions, so let's not forget the effect of the Redfield Ratio in Diatoms as well as the effects on C N and P by denitrifying bacteria. (Especially N.)

 

[ReeferBee]

I am a firm believer that cyano is caused by nutrient imbalance. Generally low to null nitrate and elevated phosphate

 

[mcarroll]

Sometimes cyano is as simple as changing your RODI cartridges (or similar), but sometimes it's a lot more tenacious.

It's not quite directly related, but this might be interesting since it does discuss parallel issues:
Bacterivory in algae: A survival strategy during nutrient limitation
(click through to the main journal article if you want to read the whole thing)

 

[jmp21677]

I just swapped out filters and my new di resin just showed up. Most of what I'm seeing is on the rocks.