River rocks
 

Have any of you tried these for a medium? The ones you buy from home depot in the bag. I am wondering if they are ph neutral.

Most all rock will be pH neutral. Some rock like Limestone or some volcanic rocks may have issues. Also some soft stones like types of sandstone, or stone with heavy minerals like salt or iron, may also have issues. But Don't think you have anything to worry about with river rock. Especially the stuff used for aquariums because aquariums need to be kept in the right pH range also.

But it should be easy to test. Simply get a small bag of it, wash it off to get rid of all of the dust. Dump the washed rock in a bucket, pour in some water that you tested the pH of first. Then check it every couple of days for a week or two, and see if the pH changes.

http://img697.imageshack.us/img697/930/bagofrocks.jpg

i did GpsFrontier what u have said
i have Ph papers
i tested all the rocks Ph level
but some of the rock's Ph didn't change

Does this mean that some of the river rocks did change pH? If so were they aquarium rocks? Also how much did it change, and was it a rapid change, or gradual change?

I have just started a DWC setup and I am useing river rock but it was from my fish tank and is like small pea gravel,I boiled it for 15 minutes before I used it and it seems to be working,but I would recomend mixing in some pearlite or vermiculite because I still have to top water daily to keep the rockwool from drying out and hope that I wont have to do that for to long,I am just starting to get roots out of the bottom of the pots,this is my first attemt at hydro and am learning as I go.If you are useing rockwool you may want to soak it in ph adjusted water over night,and double check it before you use it.that was my first lesson learned good luck

I know this is old, but I'm new here. Most river rock will be just fine if they are really river rock. It is my understanding that the highly soluble stuff from river rock is generally long gone. If a river of rain water (usually on the acid side) didn't dissolve it, your hydro solution won't either unless it's really acidic. Then the rocks aren't going to be your problem anyway.

Yes it works fine, I have had no issues with it.