@doskraut what kind of beers did you brew: Porter, Stout, Kolsch, IPA, etc? I am assuming all grain since we are in the all grain forum, so I will exclude the extract commentary. Anyhow, I would get your water tested, or try and obtain a detailed water report from your municipality. Can you elaborate on why your first three tasted so bad? It in all honesty could be a process tweek rather than a water issue.
Crystal Geyser Water looks to be spring water; which is very hard in most cases and is not suitable for lighter colored beers. To save $$ try doing a split 50/50 tap to spring. You may be where you need to be mineral wise.
R/O water is good, but you will need to (in most cases) wrap your head around basic water chemistry to see which salt additions will be needed to get your mineral content in check.
If you are four batches in A.G. brewing you may want to hone in your process before going all in on the water treatment, or spending unwarranted funds on spring water.
If you have the time and the money and the desire (the 3rd being the most crucial) try brewing two all grain stouts. One with your tap water and one with the spring water. See what (if any) noticeable differences there are and take copious notes.
Lastly, take notes on what off flavors you notice. Is it metallic, iron like, melted army men, etc. Once you have that information down, research the cause of those off-flavors and ask around. This forum is a great source of knowledge.
Good luck and happy brewing!!
