One cup in the 300 g was ok, a half pail was ok. 1 bag was ok, but the 5 bags sucked. It was extreamly fine and the tank was always murky. It killed the bacteria on the bottom of the tank before I could remove it, and I fought with the tank for 6 months trying to get rid of the algae bloom that ensued. I had only 1 fish. a large puffer. He had no interest in stirring up the bottom.
Now I have Carrib Sea - Seafloor special grade. I love it, it's like fine gravel.
I've tried lots of sand - proly 10 different types.
I got the right stuff, cuz I compared the picture I found online at the time. I got it not to long ago.
The tanks in dry dock now, I have to buff the scratches out of the acrylic.
I work with the sand and mining companies with the brickyard, So I had samples of different sand sent from all over the US at 1 point. I had a whole shelf of zip lock bagies... different people swear by different things. Just make yourself happy.
J
And yes it passed it's fizz test.