Seeking advice on plumbing rainwater tanks

[CWind]

Hi all,

I'm planning on installing a 10,000 gallon rainwater harvesting system that will consist of 4 2500 gallon tanks piped in parallel with each other (arranged in a 2x2 grid). The tanks will sit on a 4" pad of gravel topped with 2" of compacted, decomposed granite. This should be fairly stable, but was wondering if I should still make connections to the tanks with something flexible. Thoughts?

Chris

 

[Ballvalve]

All of my tanks say warranty void if not flex line plumbed for the first few feet. They DO settle.