I have started a new dirt tank using the same dirt as i have on a couple of earlier tanks. If you look at the pictures you see that dirt is the way to go if you want to grow plants not using any ferts. I have been adviced not to use any dirt containing manure, but this dirt contain 30% cow manure and it have not resulted in any agae blooms on my previous tanks.
This is the lable on the bag:
Quality Soil particularly suitable for indoor plants and window boxes. Nutritious and odorless. The earth is long time composted in 3 years, and are hand-pruned several times during this period.[censored]The result is a nutrient-rich soil full of microlife, ideal for your indoor plants and window boxes.[censored]Debio Approved for organic growers. Raw materials: 30% cow manure, 60% peat and 10% sand.
The first picture is day two, and the second picture is 10 days later. Not bad growth for a newly planted tank, it must be good dirt with premium cow manure :red_mouth Hope ou like it