The sand you ask for is Silica sand, also known as swimming pool filter sand. It is almost white, with distinct grains, like river sand.
There is also another type of swimming pool filter medium sold, called diatomaceous earth, which is white, very fine and powdery. You certainly don't want that It would make a huge mess of your tank
If you ask for silica sand for a swimming pool filter, you can't go wrong
Thirty-five years keeping and breeding discus, and I'm still learning :P
You obviously didnt get the right stuff (must ask for silica based). Yellow sand sounds like what is commonly called Sydney sand (for bricklayers), which is no good for use as a substrate.
I have had sand that is a different colour to the standered white it depends which region it comes from if the supplier picks up a cheap pallet
it may be a different colour.
Matt
Catch 22: You arent insane unless you say your insane but you cant be insane if you say you are insane.
actually looking at that photo you could be right - that particular substrate went into the garden a while ago with the new stuff being the same as yours (or whats in your photo's) but it was sold to me as pool filter sand funnily enough fine grade instead of course.
Matt
Catch 22: You arent insane unless you say your insane but you cant be insane if you say you are insane.