It's very easy to lower the ph of water. All you need is plain vinegar. If you do not have a ph pin they are not that expensive. My tap water runs about 7.0 if I add 17 cc or 1tbls plus 1/2 tsp of apple cider vinegar it will test close to 6.3. If you are adding nutes to the mix it will take less vinegar to lower the ph.