# What is the differnence between Onyx and Flourite?



## Adam (Oct 19, 2004)

Both are made by SeaChem, and all the descriptions I have seen about the product basically says the same thing about both products. But onyx is more expensive?

Whats the deal?


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## Adam (Oct 19, 2004)

ok maybe I answered my own question. From SeaChems website the only differance I can see is that Onyx has a slight hardening effect(+.1-.5 pH) on the water where flourite does not. Is this the only differance?

Also if this is the case why would you recommend using Onyx over Flourite?


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## plantbrain (Jan 23, 2004)

Aesthetics play a large role.
They seem to be similar otherwise.

Grey coast calcite is trhe same as onxy also, it's sold in 20lb bags fairl reasonable.
Generally onyx sand is cheaper.

I like the Onyx more, easy to plant stems in, dense, less flow in/out of the substrate vs other products. It's my substrate of choice, flourite next.

I add peat to counter the pH issue and encourage the reduction in the substrate.

This effects wears off as bacterial layers begin to form and stabilize the pH near neutral(this happens in all flooded soils/substrates over time).

Regards, 
Tom Barr


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## aquaessentials (Dec 15, 2004)

Adam said:


> Both are made by SeaChem, and all the descriptions I have seen about the product basically says the same thing about both products. But onyx is more expensive?
> 
> Whats the deal?


There is little difference apart from colour (Onyx sand increases kH slightly). The price should be the same unless your supplier was able to get a larger discount.


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