Since CaribSea started offering their Flora-Spore mycorrhizal symbionts I have used that product. In an established tank full of water it is necessary to make an aqueous suspension and inject it into the substrate with the provided syringe. These fungi are true symbionts and will only persist in contact with the roots. They do not intake carbon from the water, so do not have the population dynamics typical of bacteria, i.e. arbuscular mycorrhiza will not come in on rocks or fish. Any time I disturb a plant's roots, plant new ones, or re-scape I inject Flora-Spore liberally in the general vicinity just to assure their presence. There is no specific dose; there is no risk of overdose. They are obligate symbionts and can only proliferate in contact with the roots of the plants. These fungi do no harm and are not costly, so there isn't really a downside.
The market for AMF is pretty large and well-established. The species of interest are practically identical across brands. One is much like another. These are used extensively in horticulture, organic farming, and hydroponics and you can find on-line sources easily. Just Google arbuscular mycorrhiza.
I am glad to have this scientific paper. This is the first I have seen that deals with aquatic macrophytes specifically. Thanks Art!
