Another thing you can do is get a fish tank aerator. Using the air pump and letting your water sit for 24 or more hours should help out a lot with your problems. It is much cheaper than buying bottled spring water every time you need to water your plants.
You can also start to set up large containers for rain catches. It seems like if I would have done that over the last few weeks I would have enough water for the rest of my season right now.
My wife and i switched to "mostly" rain water...( We'd have to give up growing room for more water collecting, No WAY.. ) and i got to admit... we got into mid august last year before having to turn on the hose.. all added up it comes in at about 250 gallons every time it rains REALLY hard. fiskars makes a good gutter water collector, we have 3 and i drilled hose holes out to other containers as well.. similar to the global bucket water collection idea.
i don't even have my hoses attached yet. here is the global bucket thing:
not mine, but these kids rock.. i had to silicone seal up the tops of my garbage bins (mosquitos). and used plastic tubing.. but that's the coolness of it you can use almost anything.