Hi all,
This is the best chelator for iron, but expensive, which is why I assume they use a small amount.
The iron may have come out of solution if you've had the "Tropica Specialised" for a while? Particularly if it has been stored in warm, light place.
The Flourish I do have lying around used Glucate which I think is the cheapest / least effective option in hard water?
The iron in gluconate is less strongly bound than in the chelated iron (Fe EDTA) etc. which means it goes out of solution more quickly in the tank, but you can try it, it won't do any harm.
but where do you actually get Fe DTPA or EDDHA?
Have a look at fertilisers for terrestrial plants. It isn't a product I've used, but <"
Chempak Sequestered Iron"> contains Fe EDDHA, along with manganese (Mn) and magnesium (Mg). The Mg and Mn are included with the Fe because these three elements are the most likely options to cause chlorosis.
You can get Fe DTPA from <"
Gardens Direct">, and there are plenty of sellers from
<"continental Europe">.
I don't feed my plants very much, but when I do I use fertilisers like "Citrus liquid feed" etc. The reason for this is that they are
<"cheap to buy remaindered at the end of the summer">, and they are fairly low in nitrogen, so you don't add much ammonia (nitrogen source in most terrestrial fertilsers will be ammonium nitrate (NH4NO3) or urea (CO(NH2)2)).
I don't recommend everyone does this, because there are obviously risks involved.
cheers Darrel