# Dry fertilizers - shelf life



## Error (Apr 16, 2004)

Hey all.

I just pulled a bunch of my aquarium junk out of storage because I'm setting up some new tanks. Included in the lot were several bags each of KNO3, K2PO4, csm+b, and some other junk.

My question is: these ferts have been in storage and unused for almost 3 years. Are they still good? A lot of them are hard (not powdery) but they break up when smacked.

Thanks in advance for any replies.


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## obie (Mar 28, 2011)

well yeah everything breaks down over time, some just take a lot longer than others. i guess there is only one way to find out if they are still good!


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## lipadj46 (Apr 3, 2011)

the salts will last this side of forever.


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## ray-the-pilot (May 14, 2008)

Error said:


> Hey all.
> 
> I just pulled a bunch of my aquarium junk out of storage because I'm setting up some new tanks. Included in the lot were several bags each of KNO3, K2PO4, csm+b, and some other junk.
> 
> ...


Since ferts are so little of the cost in keeping a planted aquarium my first thought used to be don't use them and buy new. But then you have the problem of getting rid of the old stuff. 
The best thing would be to sell (or give away) the old stuff to someone who thinks they are OK and buy new chemicals.


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## Crispino Ramos (Mar 21, 2008)

Dry fertilizers aren't volatile compounds, I think it's ok to use them.


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## Emily6 (Feb 14, 2006)

Maybe the manufacturer knows. Call up the retailer and see what they say. I'm also inclined to guess that they would be fine as long as they stayed sealed up and dry.


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## Diana K (Dec 20, 2007)

I would go ahead and use them.


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## onefang (Apr 10, 2011)

Chances are they sat on a shelf (or in a barrel) somewhere in a warehouse for quite a while before you got them. Although they are hard, probably from a moist environment, they are probably fine. If you are a dry doser, the clumpy texture might make it more difficult to dose. You could always run them through a sifter to try and break them back into a powdered state.


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## aquaphish (Jan 22, 2005)

If these ferts are dry and not fluid, they will last for years as long as they are kept dry and not in a moist area that they can absorb moisture.

I have dry ferts that I purchased over 6 years ago and they still work just a good as the day I purchased them. 

I mix only enough as a liquid solution for about a month at a time. Then keep the dry ferts in a good plastic resealable baggie, then I place all the individual sealed baggies into a larger baggied for a double sealed enviroment to keep moisture away.

You will be fine using if they are dry.

UPDATE:

Just re-read your post. The ferts most likely came into contact with moisture at one point or the other. That is why they are hard and not in powder form. Try and use them they still should be ok. No harm will be done to plants or animals.


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