Review on 🐠 Carib Sea Aquatics Eco-Complete African Cichlid Zack Sand - 20-Pound, Black: Premium Substrate for African Cichlid Tanks by Cristina Villanueva

I was concerned that like many other black sands it might be magnetic. This can ruin your magnetic scraper and destroy the impellers in the pumps. After the magnet test, I'm happy to say that this is NOT a magnet. However, when added to water, it's a carefree mess. It's one of many foods that contain "beneficial bacteria" that aren't described in detail (species? The ones that eat and convert ammonia and nitrite?). So you say don't flush. This is bullshit (perhaps literally?). First, I've always been skeptical of bacteria in a bag, and second, I wonder how much that wet gravel would change in weight if it were just dry and pre-washed. See photo, and that doesn't go away after a few minutes either. Most suspiciously, they added a sample of water clarifier to the gravel. Clear product placement, not cool. So why 4 stars? Because the unwashed part is not so important. If it were magnetic it could be catastrophic, but it isn't. Ultimately, this is a very good gravel that doesn't do all the crazy things it claims to do, but it doesn't seem to hurt either and is perfect for a few flushes.