# chert as substrate?



## markvs (Feb 10, 2008)

Does anyone have any experience at usinf chert rock as a substrate, 
Does it leach toxins?
Does it affect pH
.....
Any info is appreciated.
Oh, I tried googling, and it only had info on geologic timescale leaching/ dissolving.


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## hoppycalif (Apr 7, 2005)

I haven't tried chert, unless some of the rocks I have used were chert. It doesn't seem to contain anything that would leach out in water. You could always put a small amount in a bucket, add water, measure the KH/GH/pH of the water, let it sit for several days, then re-measure the KH/GH/pH and see if they change.


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## markvs (Feb 10, 2008)

only one probloem, no test kits


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## MatPat (Mar 22, 2004)

markvs said:


> only one probloem, no test kits


Can you take a water sample to your LFS and have them test it for you? Most LFS will do water tests for free and there shouldn't be a problem going back in a week or so and having them re-test another sample for you


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