The tanks take up an egg shape, the most stable and strong shape with low surface area requirement, a reason they can be suitably installed underneath the driveways, paved compounds, parking lots, backyards, school compounds, poultry farms, irrigated farms and any other places where water is essential yet with limited space. Ferroconcrete tanks; box or cylindrical shaped are expensive and easily develop cracks, giving the oval type a cutting edge. Aware of the dirt on the roof for those next to roads/streets and in general after a dry spell, the tank can be fitted with ‘first flush devices’ also made on site to flush the first rain water that washes the dirty roof for about five (5) minutes, and later allows the clean water into the tank; this makes it suitable for many clean water-requiring purposes. The tanks can also be used for Runoff Farming (check website for detail), thus boosting food security and production.
Rainwater is clean soft water with trivial minerals, ensure you’re getting these trace elements elsewhere; from food to avoid deficiency.