# Question regarding inert substrate fertility



## murdocmason (Aug 17, 2009)

well the question is can I use dry fertilizers ex. Kno3, kh2po4, plantex CSM+b, magnesium sulfate, k2so4 under the substrate to increase the fertility?


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## murdocmason (Aug 17, 2009)

if so which ones?


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## Diana K (Dec 20, 2007)

You probably can, but in very small doses. These dissolve very readily, and even the very small water movement under gravel or coarse sand may be enough to dissolve them and move them into the water column. A very tiny dusting under finer substrate might be OK. 

A better way to use them is to incorporate them into clay balls or other DIY tablet sort of thing. Then there is more control over how long they last/ how slow they dissolve. 

I would not mix any iron containing product with any phosphate product. Certain combinations result in an insoluble precipitate that is no good as fertilizer.


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## murdocmason (Aug 17, 2009)

thank you very much for the info I went ahead and put a tiny dusting of plantex under the substrate and there is only going to be plants inthe tank so it shouldnt be very bad if something does go wrong lol


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## niko (Jan 28, 2004)

If you don't know that it will be interesting for you:

Good planted tank substrate, as any soil really, is a complex system of chemicals and living organisms. Through their interaction your substrate gets "good" or "bad" for plants. An inert gravel has very much the same effect as AquaSoil after a year or two of uninterrupted development. That's because after some time your substrate is alive. It resembles real, natural soil. It's a microscopic civilization with it's ups and downs of "nations" and accumulation/depletion of "resources".

What all that tells you is that being patient and establishing your tank + substrate properly is the only correct way to run a planted tank. You can try adding fertilizers in it and have some success. But nothing will force the natural processes to happen much faster than Nature intended. I could even say that "time is the best fertilizer".

Here's an example (read the comments under the pictures):
https://picasaweb.google.com/ddasega/Mike#5251596256994513810

--Nikolay


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## murdocmason (Aug 17, 2009)

thx niko for the info your always a good encyclopedia of aquatic information =)


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