Is this £1 plant Food usable?

[nayr88]

Hello guys

I was in the pound shop (great for wabi bowls) and came across a packet of 'eazifeed Soluble Plant food'
its just looks like yellow salt, I have very little idea about nitrogen potassium ect ect, this is sold as an NPK plant food witch is what made me think could I use this in my tank? This is the ingredients as they read on the packet.

The packet is 250g by the way:

15-5-30 plus trace elements
Total Nitrogen 15%
Ammoniocal Nitrogen 6%
Ureic Nitrogen 9%
Phosphorus Pentoxide (P2O5) 5%(2.2%p)

Soluble in neutral ammonium
Citrate and water 5%
Potassium Oxide (K2O) 30%(24.9%k)
Soluble in water 30%

It says for indoor use, half spoonfull (2.5g) into 4.5Liters....

Please don't shoot me down for posting this, I'm still getting my head around dry salts ect and for a quid even it its not usefull in the tank ill use it with outdoor plants like its ment for haha

 

[ceg4048]

Hi mate,
NPK is NPK, but having said that, whenever contemplating any terrestrial fertilizer, one has to think carefully about the Nitrogen source. Almost any form of Nitrate (NO3) is low risk. Powders such as Magnesium Nitrate (Mg2NO3), Calcium Nitrate (Ca2No3), Potassium Nitrate (KNO3) will dissolve into their constituent parts, i.e. Magnesium Nitrate will dissolve into [Magnesium + Nitrate], Calcium Nitrate will dissolve into [Calcium + Nitrate] and Potassium Nitrate will dissolve into [Potassium + Nitrate].

So what do you think Ammonium Nitrate will dissolve into?

If you reasoned [Ammonium + Nitrate] then you're right. So now what? Nitrate is no problem. We have shown that you can dump boatloads of Nitrate into the tank with little or no risk, but what about Ammonium? We ll, we know that it's about 700X more toxic than Nitrate right?

So if the source of Nitrogen in a fertilizer is Ammonia/Ammonium you have to exercise great care if there are fish in the tank. If the source of N in a fertilizer is Urea, then we know that there are enzymes in the tank substrate that will convert the Urea to Ammonium. Again, in small doses Ammonium is a powerful and highly efficient source of Nitrogen, but if you miscalculate when dosing this fertilizer, then you'll be making THE mistake and you can easily wipe out your fish.

For terrestrial plants this is not a big deal, as there are no fish involved. If you know what you're doing then it's also not a big deal. Just about all of the commercial fertilizers, even aquatic brands like Seachem, Profito, ADA and Tropica use Ammonia based products for some of their sources of N, however, as we know, they are very dilute, so it doesn't matter too much when dosing these products. The bottle suggested dosings on some like TPN+ are also weak, which effectively gives the user an extra margin of error.

Cheers,

 

[nayr88]

Nice one Ceg, really well explained. When I was typing out ammonium I had an idea it might be the downfall haha.

Thanks again mate