| Re: Blackouts/algea boom
A second blackout IMO will probably not do any harm. The real problem is the green water will probably come back.
I am doubtful that high NO3 in a planted tank is going to cause you a serious problem. The problem is your green water will probably come back again.
In all probability what is happening is that you have a situation where the plants and algae are coexisting. This usually indicates that you do not have robust, healthy plant growth or sufficient plant mass to dominate the algae. I have preached over and over that when you start a "well planted tank" load it with cheap stem plants and establish a plant bio mass that will inhibit algae growth.
And as far as chemistry is concerned in a well planted high light tank. it is almost always the lack of a crucial nutrient that triggers an algae bloom not an abundance.
Let's deal a little with the concept of plants being dominant. How can they be if we have a water column full of nutrients algae love and lots of light to help the algae produce energy? I have seen "Tom Barr" a very respected plant researcher and guru use this example.
A group of Elephants (plants) and a group of mice (algae) in a confined space.
Both the Elephants and mice eat the same food. If the Elephants are under nourished, not feeling well and are lethargic then the mice are going to take advantage, multiply and feed. If the Elephants are healthy, well fed, and robust the mice are going to get out of the way, retreat, hide etc. This is the basic bio-dynamic that takes place in a well planted aquarium. The lesson...grow plants, fill their needs and the algae will diminish.
You need to think about this concept, everyone gets a little green algae on the glass, but if your PO4 bottoms out watch out. Also the consistency of your CO2 injection is crucial.
If you are having recurring green water you are missing something, take a step back and a hard look.
Jay | 
