If you really dislike the taste of water in the hydration systems, you may want to try putting in a drop of an essential oil, like peppermint in the water. This is what I do. It is very refreshing and may help you with any unwanted tastes. You WILL have to clean the water bladder out every few days, depending on you level of tolerance. The longer into the Camino, the lazier I get and the less I care!
When on the Camino, I rinse the bladder with soapy water, then fresh water, to clean it out as best as I can. Then, I stick the tube inside the bladder to keep it open and hang it in the sun so the UV light can kill any germs and hopefully dry it out completely. Works pretty good. Then when at home, I use a bit of bleach in water to clean it, rinse it extremely well and hang it in the sun again.
OR, you could just use disposable water bottles and buy new ones when it gets too bad. Seems to me that this would be your preference anyway. Or more environmentally friendly, would be a reusable water bottle that has a wide-mouth that you can get your hand into to clean it. But, I am afraid that you may not like the regular water from the tap. You can drink tap water in Portugal, but I always ask wherever I fill, to be sure. Sometimes they tell you it is safe, but it won't taste too good.
Good luck and Buen Camino!