# Vermiculite in substrate



## fishcrazy (Feb 15, 2006)

has anybody mixed only vermiculite to their gravel and had success?? if yes, is there a big difference than w/o it??


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## AaronT (Apr 26, 2004)

I wouldn't do it. It'll all float to the top of the tank every chance it gets and you'll be netting it out for eons.


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## plantbrain (Jan 23, 2004)

Bad idea.

Regards, 
Tom Barr


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## dkfennell (Apr 19, 2005)

Vermiculite has to be rolled into something the consistency of garden loam in order to stay down. You do it by kneading wet vermiculite into slightly moist dirt, as you would a pastry dough. If you don't roll it into something like dirt, it will, as everyone has suggested, float. There's no way to waterlog it.


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## fishcrazy (Feb 15, 2006)

I was testing some of the vermiculite i got from my garden center. i found out they sink after a week soaking in water, however i haven't crushed it up yet, so maybe they'll start to float when i do.

are there any benifits of having vermiculite mixed with the gravel?


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## AaronT (Apr 26, 2004)

There's no benefit really. It's in soil to provide aeration. You should get plenty of that with just plain gravel.


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## dkfennell (Apr 19, 2005)

The possible advantage would be to provide a very high number of cation exchange site where roots can "exchange" H+ for nutrient cations that the clay holds (K+, NH4+, Ca++, etc). Vermiculite has a much higher cation exchange capacity than laterite, and even, I think, peat. 

Now whether has any proven benefit (particularly in our tanks where we add a veritable "soup" of nutrients to the water column), I don't know, nor have I seen anything empirical on it. I will say when I replanted plants into a substrate with vermiculite and peat, I got very good initial growth and within a week I got blossoms (although this might have been due to a change in the photoperiod). I personally also think it's easier to root swords in clay than in gravel. But I don't do a lot of moving plants around, so I look for more or less permanency in a rooting medium.

Darrell Fennell


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