Water sourced from the tap can contain too much chlorine. Chlorine gets added at the municipal reservoir to kill microorganisms and bacteria to make drinking water more safe for humans. For plants, high levels of chlorine are harmful to their root zone and therefore should be removed. Before adding any fertilizers, remove chlorine from your tap water using a chlorine filter. Vitamin C (ascorbic acid) tablets will also get rid of chlorine.
Fertilized irrigation water can attract fungi infections that consume nutrients. This is bad because fungi destroys fertilizer so plants can’t use it. Prevent fungi colonies from developing by adding sodium benzonate to the irrigation water at a concentration of .13 gram / 100 litres.