ferric or ferrous is better?

[wllm33]

hi,
any expert can give tips on whether the iron suitable for plants is in ferrous or ferric form?
and if one of the above, can a tablet for human consumption be enough to be soluble for use for plants if drop inside the tank and how much will be soluble, or they should be in a certain form to be soluble.
noobie here.
thnks

[Laconic]

If I'm not wrong, the ferrous form (2+) is soluble in water and so available to the plants for foliage feeding. Ferric iron (3+) is insoluble and will precipitate in the water column, hence rendering it unusable for plants.

Most commercial brands of ferts use ferrous iron that are chelated.

As for tablets meant for human consumption, I highly doubt that its advisable to 'drop' it into the tank.

[wllm33]

If I'm not wrong, the ferrous form (2+) is soluble in water and so available to the plants for foliage feeding. Ferric iron (3+) is insoluble and will precipitate in the water column, hence rendering it unusable for plants.

Most commercial brands of ferts use ferrous iron that are chelated.

As for tablets meant for human consumption, I highly doubt that its advisable to 'drop' it into the tank.

thanks .
no wonder i keep seeing ferrous in the commercial products.