first of all, hi, this is my first time on this site, but i will take a minute and explain a few things to you..just bebause you are like myself, irish ;0)
ph is everything...you have to keep it in a certain margin to allow the plants to intake what it needs to grow. simply put, evry plant has a beloved ph value. and for weed, this ph = 5.8-6.5 in water, and 5.4-6.2 in soils. dont mind what other ppl tell you, remember this,and i promise u success!!
its great you have a water softener,this will keep your EC low,and allow you to add as much as 2.5times as much food as normal, without over-feeding your loved ones
but this is another topic, and if you like, i will explain another time.
if your ph is too high, or low it will take in too much or too little of vital elements the plant needs to survive! ...you will find yourself dealing with all sorts of problems and in the end you will stress yourself and the plants and your hard work will be in vain
get a ph meter.!! now!! im not sure where you are living, US? europe?
the cost of these things vary, from about 10, to 300 euro's. a device in in the middle price range (50) is ok for hobby growers. know how much feed you will need to make to water your plants. allow this water to sit for 24hours to loose whatever chlorines it contains, and the ph value should also drop by a small ammount. at this time you can add your foods,or nutrients to the water, correct the ph (there are many ways to do this,depending on the system you have,soil? hydro?) and then, you may feed your plants.... this may seem complicated, i know, but tell me what you plan to grow, and with either soil or hydro system, and i will tell you more.
hope this helps more than it stresses ,
H stayed stable.