Originally Posted by compulsion
i just wondered if P2O5 (phosphorus pentoxide) can be used as a substitute for pottasium phosphate. i gather the amounts to dose will change.
heres the analysis:
J. Arther Bower's SUPERPHOSPHATE Plant Food.
Phosphorus Pentoxide (P2O5)
soluble in neutral ammonium citrate and water 17.5% (7.6% P)
of which soluble in water 16.5% (7.1% P)
Also this one:
J. Arther Bower's Sulphate Of IRON Plant Food.
Iron (Fe) 20.0%
it doesent say it contains any EDTA's or the mention of chelated anyware on the boxs, just those details above in the analysis box.
no worries if not, i just found them in the garden shed
Superphosphate is usually a calcium phosphate compound or mixture. Phosphorous pentoxide is very reactive and produces phosphoric acid on dissolving in water - it is not sold as a fertilizer.
Fertilizers report their content the same way we report GH in an aquarium - GH is both Mg and Ca, but we report the degrees or ppm of CaCO3 EQUIVALENT to our amount of Mg and Ca. In fertilizers, phosphorous content is reported as the EQUIVALENT percentage of P2O5 - regardless of the actual chemical form of the phosphorous in the bag.
From the label, the iron is in the form of iron sulfate. It is PROBABLY FeSO4 (Iron +2), but might be Fe3(SO4)2 (Iron +3). It is an inorganic salt, not a chelate. Could still be used in the aquarium - just may oxidize and precipitate out more quickly than a chelated iron. Fine for root-feeders, not as great for stems.
ABOUT BOTH ITEMS: If the ingredients aren't listed, it will be risky to use it in your aquarium - what additives may also be in the bag?? What is fine for terrestrial plants may not be so great for your fishies!
72g bowfront planted, CO2, 4x - T5HO, Eheim 2213 and 2217, 2 angels, pristella tetras, blue tetras, betta, albino bristlenose pleco, albino cories. Sword, vals, hygros, ludwigias, java moss and fern, anubias
2g Mac-quarium. Clown gravel, fluorescent plastic plants, and 2 guppies.