tap water has many irons and chemicals in it especially when you make the mistake of using warm tap water to try to bring down tempts to room temp all in all ditch the tap water and buy gallons of water poland spring deer park there 1.50 a gallon had the same problems myself also could be poor soil quality as for the above advice of feeding them i dont recomend that unless u wanna fert burn and throw them into shock for a couple weeks best of luck