I would DEFINITELY go with pool filter sand over that stuff. You can wash that bag for an hour and the tank will still be cloudy for a day of two and the grains are really small (easily stirred up, can end up damaging filtration, compacts and forms gas pockets easily). Pool filter sand is larger grained, doesn't compact, doesn't get stirred up much, and you can dump it in straight from the bag without much if any clouding