What is the preferred backfill material for fiberglass reinforced plastic tanks?

The preferred backfill material for fiberglass reinforced plastic tanks is pea gravel. This material is advantageous because it provides good drainage properties while also allowing for even distribution of load around the tank. Pea gravel is less likely to compact over time, which is important for maintaining the structural integrity and stability of the tank. Unlike sand, which can shift and collapse, or clay, which can retain water and cause pressure issues, pea gravel offers a balance of support and drainage that is ideal for the specific needs of fiberglass tanks. Using pea gravel helps minimize the risk of damage from settling or shifting soil, ensuring the tank remains secure and functional over its lifespan.