Dino and Cyano
Finger crossed, I don't have an outbreak now. However I do have several encounters with out of control dino or cyano bloom, and had overcome them successfully. I would like to share my thoughts, and debunk some myths about cyanobacteria and dinoflagellate.
1. My Tank Don't Have Cyano/Dino
Unfortunately, or fortunately, a population of cyano, and dino, are always there in our aquarium. The number maybe very low, and invisible to our eyes, but they are there. As certain as their are bacteria in your biofilters and rocks, the cyano and dino are there on the rocks, sand bed, and glass. The only reason stopping them from growing out of control is the rest of the bacteria, algae and corals, competing (successfuly) against them, keeping them in check.
2. Cyano and Dino Appears when Nitrate and Phosphate is Zero
This is one of the most repeated statements about cyano and dino. However, I think this does not represent the full picture.
Cyano and Dino are living organisms which requires nitrogen and phosphorus elements to grow and reproduce, just like any other organism does. So if one start to believe that the lack of nutrients leads to proliferation of these "pests", one is mistaken. While cyano is able to fix nitrogen from dissolved gas, all of them requires phosphorus from their enviroment. Therefore. If there is no phosphus available, neither cyano or dino can strive.
Then how do we reconcile the fact that many reefers observe cyano or dino outbreak, when their nitrate and phosphate levels are zero? Look back at my previous paragraph, these organism needs nitrogen and phosphorus, but not necessarily in the form of nitrate and phosphate. Our test kits cannot detect other forms of nitrogen, nor organic phosphates. Therefore, conceivably the aquarium can at the same time be NP rich, yet detects 0 on the different test kits.
What can possibly lead to this situation? One of the possibility lies in disruption of food chain, where heterotrophic bacteria population is suppressed. In the absence of these, organic compounds remain in the aquarium, the inorganic salts remain low, and many nutrients are available, and preferred by cyano and dino.
3. Medication
Many reefers recieve the advise to medicate when faced with blooms. Many discussions have taken place regarding both the efficacy and safety of various treatments. While I believe many treatments can effectively and safely suppress the cyano or even dino, I am against medicating against these organisms.
The reason is simple. These organisms thrives because of available nutrients in the aquarium. When they grow, they actually takes up these nutrients and fix them in their bio mass. If we were to kill them through medication, these excess nutrients are onces again released into the water column. It may solve the symptoms of algae bloom, but it does little to address the source of the problem.
I advocate physical removal of the offensive algae through siphoning, into a filter sock in the sump. This way, we have the confidence that whatever offending nutrients is removed from the system for good.