There are two low tech CO2 systems extant. One, an inverted bottle diffuser, is for ONLY small low tech tanks under 20 gallons (80 liters). The second, a “wide mouthed jar” diffuser, will work well for much larger aquariums. These type systems are often called “passive CO2 bottles”.
Carbon Dioxide and Plants in the Aquarium: Unless one has some very easy aquarium plants (Anubias, Amazon sword, Java fern, Java moss) a planted aquarium needs a source of carbon dioxide.
Some hobbyists with planted aquariums want to use the same type of fertilization program an expensive commercial aquarium fertilizer will provide, but at a much lower cost. This article tells on how to make a do-it-yourself fertilizer which is MUCH cheaper.
Adding a “natural” fertilizer like extra fish food is not a good idea if there is little biofiltration together with fish in the aquarium. The “natural” fertilizer produces dissolved organic compounds which feed heterotrophic bacteria.
DIY Epiphytic Fertilizer: Some planted aquariums have epiphytes (plants that grow on wood or rock) and floating plants. They have to be supplied phosphate and iron through the water column.
NH4 + Tabs Aquarium Fertilizer: a guide to making a series of do-it-yourself (DIY) fertilizers for aquariums.
The Estimative Index (EI) method is the most popular method of dosing fertilizers in high-tech planted CO2-injected aquariums. I find it to be somewhat complicated and very time-consuming to implement. But there is no question it will give one a very beautiful high-tech planted aquarium.
There are several planted aquarium commercial fertilizer “lines” of several products, all designed to be used together in a “program”. Easily 80% of the “fertilizers” in “programs” are pure unadulterated snake oil designed solely to get you to part with sizable chunks of money.
Ready Made Fertilizers: The easiest approach to planted aquarium fertilizing is to simply use Aquarium Co-Op Easy Green™ per the instructions on the container. Easy. Simple. Reasonably effective but expensive.
Cycling a planted aquarium is tricky. If the plants start growing from the get-go the plants can absorb the ammonia before the beneficial bacteria can get to it.
