Good source of cheap gravel

I decided to convert a couple of larger tanks from rocky hardwater biotopes to rainforest tanks. The big issue I had there was my gravel. I had used gravel from the hardware garden centre, as it released a lot of minerals in the water. That's what I wanted then, but really don't want now.
My beloved lfs has aquarium gravel at $20 for 25 pounds. Doing two tanks would cost an arm and a leg, and while I like to support them as much as possible - that is beyond possible.
I found a couple of pool supply stores locally. The first had sharp silica gravel - too sharp for digging fish not to be harmed by it. The second had a dark grey gravel of a perfect size - and of a colour that would really show off the fish. It was at $7.99 for 50 pounds.
I bought a bag and brought it home. I took some and put it in a jar to test it. In the US, all pool filter gravel must be chemically inert. In Canada, or at least in my corner, I know of no set standards. The info on the bag was not detailed, but it did claim to fit the standards of all filter manufacturers and their guarantees. So I figured I might have bought neutral, inert rock.
Bingo. There has been no increase in hardness over 48 hours ... and I have a source of cheap and nice gravel.

I see aquascaping in my future.

When I was looking for sand, I googled pool stores as well and couldn't find any.... Now pools on your side of the island are more common than on mine, but still...

I ended up buying sand in Rona and although a bit lightly coloured it turned out to be good quality and I didn't lose much during the rinsing.

Do you think that your gravel would be suitable for cories?

There is also another pool store that carries white sand. Its rather nice. I think its at 11 for 50lbs though.