What you are thinking of is usually called "pool filter sand" or "play ground sand" (or just "play sand"). Play sand tends to be a little less clean and smaller grain. Make sure you rinse it as much as possible.
It won't cause algae problems. It may fuel a little more diatoms then usually but it isn't quite the apocalypse like many people make it out to be.
There are some arguments over it being bad for sand-sifting livestock, but this seems to be one of those opinion-based arguments. The simple fact is that silica sand exists within the oceans and sand-sifters do deal with it in the wild. Whether it hurts them more then aragonite is arguable but it won't kill them.
The key issues with silica sand are that it doesn't offer the buffering or nutrient advantages of aragonite.
It may also have a higher chance of causing scratches to the glass, if you allow it to get into a situation where it can scratch the glass.
This is one of those subjects that dies quickly under a barrage of "stop being cheap and spend more money" type responses. There are two schools of thought in this hobby. One believes in always spending extra for quality and correct usage. The other makes use of cheaper alternatives as long as they can minimize risk. The first group will always answer these types of questions with "why take the risk?".
