# Onyx gravel or sand?



## louieknucks (Oct 12, 2004)

Hi everybody, I'm new to the forum and to the hobby. I have a 20 gallon tank and am looking to add live plants to it. I want to start off by getting some good affordable substrate. I've come down to either Onyx gravel or the sand. Is there really any difference between the two? Which one do you think would be better from personal experience?

I know that is a lot to ask but any help would be much appreciated.  Thanks!


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## niko (Jan 28, 2004)

Onyx is not inert. It will alter your water properties by adding chemicals to it. Some say that that is for good. 

I personally would get some inert pool filter sand - $10 for a 50 lb. bag. That or Fluorite which will also not affect the water.

--Nikolay


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## plantbrain (Jan 23, 2004)

I've used onyx for a number of years now, it's my favorite substrate overall for planted tanks.

You want the sand, not the gravel.

Grey coast calcite also by seaChem is the same thing, comes in 20lb bags.
20-30lbs will be good, I'd add 30lbs myself.
So that's about 30$ or so depending on the local vendor, or you can order on line etc also.

Add some ground peat moss, about 1 good wetted handful.
Add some mulm(the dirt that settles in the bottom of a bucket after a deep gravel vacuuming) to seed the new substrate.

Fill the tank carefully.

You are now done and need to plant tha tank heavy with lots of plants.

Onyx/flourite does much better with plants than inert silica sand.

I know silica sand and sand with CaCO3 in it very well with many species.

Regards, 
Tom Barr


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