I currently breed RCS rather successfully, and am now getting more serious about breeding more shrimp species. I'm pretty sure I will stick to the harder water species, for example yellow H. heteropoda shrimp and green shrimp (C. cf babaulti). In the future, I may try Amanos, if I feel braver then

So my readings out of the tap are KH = 8 degrees (~140 ppm), GH = 13 degrees (~240 ppm), NO3 = 5-7ppm, PO4 = .25-1.0 ppm. The last two fluctuate a little from time to time within the ranges I list. The nitrate and phosphate values aren't great, but so far the RCS have had no complaints!

What are the other parameters one should examine when making the decision to purchase an RO unit? I am willing to purchase whatever test kits you all recommend, but have heard that inverts will die before copper levels reach detectable concentrations.
I live in an agricultural area so am worried that there are all kinds of pesticides or other nasty chemicals in my tap water that I can't test for. The local environmental report lists our groundwater as having trace amounts (~0.5 ppb or micrograms/L) of things like toluene and benzene.
One last question:
How about the bottled water you can get by the gallon (fill your own container) for $0.30/gallon? How trustworthy are their RO filters? I think I read badflash said their UV sterilization is useless.
I definitely wouldn't rely on this source long-term (if you want something right, you gotta do it yourself), but for the short-term is that an acceptable alternative? Even if I don't end up needing RO water, I'm just curious about this source of so-called "pure" water.
Much thanks!