I am having problems with my 100gal fw planted tank. We are in a major drought here in Corpus Christi Tx. I have requested an analysis of what is in our tapwater from the city. I believe that they are putting something in our water supply that is inhibiting the growth of my plants. I use the EI method and had no problems untill this drought started to take its toll in our area. I was thinking of investing in a small RO system so I could mix 50% tap and50% RO. Am I on the right track? As I said I so far dont have an analysis of our water yet. The last analysis the city has posted online is from 2007. Any help about RO systems etc. would be appreciated. Thank you.