Everyone has the right to know what elements and/or contaminants end up in their source water so "knowing" is irrelevent, but asking the right questions is. I do agree that certain areas would probably benefit from RO
in comparison to their tap, but not all water supply lines are created equal. That being said, what standards of toxicity are you referring to? Very little controlled data has been corresponded in metal toxicity and even that of which has, is bound by speciations and usability. In case you are wondering, all I am stating is to be careful when making a general statement about metal toxicity in tap water when such genuine information is next to nil.
Obmanta, do have them check PO4
(Phosphate) as I'm sure everyone here will ask anyways - bleh, too late. Perhaps I missed it, but other than a rusted bracket needing replacement, what is wrong with your plumbing? What does your wet/dry consist of? I agree that the NO3
is probably from the skimmate return if you were producing quite a bit of liquid plus any excessive feeding and improper water changes. I would perform a 25% water change (gravel vacuum), refill, and wait for a couple hours to see how your animals react. If all normal, another 25% would be in order (gravel vacuum another section).