There is the possibility of integrating the amount of carbon available to plants in the aquarium, through the use of certain chemicals sold by companies acquariologiche.

The normal source of CO2 in the aquarium are the tank with plants of various sizes (on average between 500 gr. And 2 kg), with pressure regulator and gauge, needle valve and then maybe diffuser or atomizer to send in solution as much can carbon dioxide.

But there are products that integrate organic carbon, are liquid to be added periodically to the aquarium EVEN in addition to CO2 gas as the Carbon Plus Azoo and Seachem Excel (Dell'Azoo that costs far less. Maybe those who are just fond of Seachem can find abroad and save a few euros).
These products do not contain phosphates or nitrates, and read feedback from the Net, it seems that both work well, provided that at s'impari dosarli well ... a bit 'like all the lines pushed for the fertilization of aquatic plants.
I conclude by asking those who have had experience with this type of products for fertilization, or will begin soon experience, to write some comments useful for all, not so much to investigate the chemical, the more tricky, as to the advantages, disadvantages, dangers of using real.
In fact even when I have not tested these products, I think I started in a small aquarium in the bathroom during the month of September.