Causes of Cyano Algae ?

[jdieck]

While light filtration only reduces certain wavelenghts the only thing that can actually shift the spectrum is changes in the chimistry of the plasma inside the bulb.
One thing I agree is that although there could be some effect of the spectrum changes over the algae (good and bad) the first thing I would look at would be Nutrients specially nitrate, phosphate and organics as I mentioned in my first post above:
The main reason for Cyano is high nutrients (Nitrate, Phosphate and Organics), contributing factors to it's spread are poor skimming low or shifted spectrum lighting, slow flow, over feeding and poor nutrient export and poor general husbandry.

General actions include:
a) Vacuum out as much of it as possible
b) increased water changes using RO/DI for your salt mix
c) Increased skimming (larger skimmer, second skimmer and / or wetter foam)
d) Increased flow circulation
e) reduced feeding
f) Use Organics adsorbing media (Like Purigen)
g) Blow off detritus from rock pores while running the bag or a mechanical filter
h) use of a refugium with macroalgae to increase export
i) Improved pod and sand shifting critters to improve upon a functioning deep sand bed.

Once you have worked out the improvement in the conditions basically to prevent its recurrence, if it does not go away you may need to treat chemically.

 

[chucksta1]

I would really like to know the other part of "where" does it come from. If a tank is a closed system (nothing gets in that we don't put in), where does the cyano come from? Is it introduced in food? water from the LFS with a purchase? It may well grow and multiply if the conditions in a tank are favorable, but where does the bacteria get introduced in the first place?

 

[dnjan]

Where do practically all of the nuisance algaes come from?
Live rock, live sand, porous plugs that corals are attached to, that little bit of tank water (from a different tank) that somehow got into the tank when you bought a new coral, ...

I had live rock over two years old suddenly start growing feather caulerpa when the nutrient level got too high. Those spores, etc. can apparently stay dormant for a long time. So normal quarentining will not protect you from nuisance algae.

 

[CrackerFish]

I attended a seminar by Sanjay at CMAC in Columbia SC and I'm pretty sure he said spectrum shift is a misconception, FWIW. It does not happen. Now I hear this all of the time, even my LFS guys believes this, and I respect his knowledge, he has been into fish keeping his whole life, and is very knowledgeable. He also attended this seminar with me, but my money's on Sanjay.