Iam using a 15. Ltr min at present used it a while buffering from a 210. Garden tub Iam thinking of upgrading to a 21 ltr when I switch the water on from the garden tap to buffer tank. I keep the garden tap on then switch machine on keeps the tank almost level in the 15 ltr machine which is fine
So on a 21. Ltre min. Are you operators emptying the tank while the machine is on and having to wait for it to fill. Because there's a big difference from 15 ltr. To 21 ltr