Hi,
I apologize for typing in English. I hope that if you are interested in what I have to say you can find an automatic translator. I use Google Chrome's built in translator function to read your forum.
I am glad to see the topic of organics discussed. I had discussed the topic of organics and algae with JeffyFunk and the result of these discussions was the experiment mentioned in Bocap's post that started this thread.
I've been interested in the role of organics in the planted tank for a few years. In the USA the planted tank hobby is in a crisis. The American hobby is very active but there isn't a lot of understanding how everything actually works. People only think about equipment and fertilizers. Equipment and fertilizers are not the only things that make a planted tanks work.
Organics can cause algae and in most tanks algae are a constant risk. Reducing the organics helps but it not a guarantee that the algae will disappear. Also there are tanks with lots of organics (many fish, lots of food, and even yellow water) that are completely free of algae.
There is a connection between the health of the plant leaves and the organics in the water. I believe that plants are actually worst polluters of the water than fish and fish food. Stressed plants can quickly release "juices" in the water which are definitely "organics". But what makes them especially bad is that these juices seem to invite algae better than fish waste or fish food.
Again - in some tanks with lots of fish and yellow water apparently there are a lot of organics but there are no algae. I have two tanks like that and it it very strange to see how stable and clean they are. Not a single spot of any kind of algae for 6 years!
Why it is possible to maintain a tank very clean but algae still comes? Why it is possible to keep a dirty tank but no algae appears?
I believe that the answer is very simple but also hard to use in real life: In a planted tank it is important to establish certain processes, certain interactions. But for most people it is more important to add or remove certain components (add fertilizers, remove waste). The aquarium is a dynamic system and the interaction between the parts is more important than the parts themselves. A clean and easy to maintain tank is exactly that - a well functioning system of interacting parts.
Because the planted tank is a system of interacting parts it is very hard to find a balance. Everything can change very fast! The best approaches to maintaining a planted tank that we have today are based on adding or removing substances (removing waste, adding fertilizers). But that is only the beginning of the actual process. What are the reactions inside the tank is not known well enough. For example we all know that Phosphate and Iron react with each other, but we do not know how and why organics dynamically bind and release fertilizers!
Simply put in our tanks there are more unknowns than the amount of fertilizers, amount of waste, and amount of organics. Organics are not easy to understand - depending on pH, concentrations of chemicals (O2 for example), redox potential, electromagnetic fields etc. these organics can hold or release other substances. This means that the tank is constantly changing because of reactions between the biochemicals in it. And the plants actually need these biochemicals! This is not about keeping a tank organics-free. This is about establishing the tank properly.
So removing organics from the tank is not the best idea. The best approach is to establish the processes that make the tank work. The steps to establish these processes require patience and consistency. Inconsistency is a big problem - for example most planted tank enthusiasts change water too often. This is very disruptive to the tank establishment. In fact most tanks that we see on pictures on the Internet are very unstable and can not exist without care for longer than one week.
Below are some important things that lead to a properly established tank (set up an environment where unknown processes keep the tank stable and algae free):
1. Establish even water flow
2. No damaged leaves ( no holes, no fertilizer deficiencies)
3. As little water changes as possible
4. Very slow start (the tank is not established until 6-8 months!)
5. Gradual introduction of CO2, fertlizers.
6. Filter media that does not need frequent cleaning
In the maintenance of the tank there are more things that will make it unstable. But what is important to understand is algae will never appear if the processes are working well. Algae will appear if we are only thinking about concentrations of chemicals (removal or addition).
--Nik
