Tank Substrates That Sabotage Your Plants There are three main types of substrate: special soils, sand, and garden soil. Some soils lower pH or release ammonia, which can harm fish. Sand works well if you add a base layer with nutrients. Be careful with garden soil, as it may cause algae. Follow for more tips on how to maintain a healthy and thriving planted tank. #AquariumSubstrates #PlantedTankTips #DrTimsAquatics | DrTims Aquatics