Guys thank you very much for your time and advices!
My another issue is the CO2... Obviously I will use low-tech plants, but they still need some... In the book she describes CO2 releasing from decomposition of organic matter in the dirt, but eventually this CO2 will also be depleted in couple of months.
Do you have any thoughts and ideas about adding regular sources of CO2 supply, organic matter to substrate n.1 or to substrate n.2 that I described?
Im worrying about fast growing plants that are meant to be the stability aspect of the aquarium - that they will slowly dissapear over time, because there will be no regular source of (even low) CO2.
There is CO2 in the air, by promoting gas exchange, increasing/aerating water surface you are promoting the exchange of O2 and CO2 from the water.
Plus during the night plants do not consume (significant) CO2 since there is litte light to perform photosynthesis, but still consume O2. This is why people usually don't run CO2 at night.
getting more complex with plants becomes the carbonate cycle (KH) and uptake requirements, etc.
[/QUOTE]As a ferts, fishfood will be used, but I have to figure out what kind of fishfood have all the nutrients and calculate the values etc. ... [/QUOTE]
This may not be as easy as X in and X out.
Meaning minerals/nutrients "IN" doesn't mean that it will be available for your plants. Its complicated, but simply a fish may eat fish food, need 30% of calcium for bone growth and excrete the remaining 70%. That 30% of calcium is unavailable to the fish tank until the fish dies and you left it in the water to decay. Now multiply that by each animal in the tank calculating growth... complicated, right.
Thats why testing and dosing is so popular.
I like the green sand Idea, I will be stealing that for my tank Thanks.
Hope that helps alittle.