mimina82, welcome. Regarding apple juice, I actually stopped using it a few weeks ago. Even when I did use it I only used perhaps 100 ml (unsweetened apple juice) in each shake. I used to also alternate between apple juice and pear juice.
Now the reason I stopped using fruit juice is because they are too sweet, even if they are 100% unsweetened juice. My strategy is to make the shake only sweet enough to be palatable. And so I simply put in limited quantities of pineapple chunks, berries and/or a banana to achieve this. Therefore I recommend if you cannot find unsweetened apple juice then go with filtered water and fresh (or frozen) fruit instead.
totoro, steelem: it sounds like my shakes, at 2 pints each, are puny compared to yours. Admittedly my shakes are very thick but I like them this way. I can also consume the entire shake in one sitting, albeit it takes perhaps 20-30 minutes.
_Lazza
