Santizing fresh water tanks

[Junmy3]

Getting ready to head out on our big summer trip and need to sanitize the fresh water tanks for the first time. My previous camper only had one fresh water tank, but my Jayflight 27RLS came with two. On my old camper you just put a small amount of bleach for the proper number of gallons. With two tanks how do you get the proper amount into each tank?

[oldmanAZ]

The two tanks are joined at the bottom. There is no valve and the water flows between them.

Calculate it as though it was one tank, pour the diluted bleach solution into the fresh water fill, and then fill up through the fresh water fill. Then run your pump and open faucets to run the sanitizing solution though the system.