I have been growing since 2000. For like 2 years , when I first started, I grew with nothing but miracle gro and tap water. I had decent results. I was growing Serious seeds AK47, Dutch Passion skunk #1 (I believe???) and world of seeds. I really had no real problems.
After that I was I was introduced to FFOF and started growing in that, by that time , I had a bunch of elite's stuff, cali connection, and the white clone only when krome came out with it. It was straight FFOF and tap water in 3 gallon buckets. Never had one single problem when I watered with straight tap water. I grew out a 13 week Kali Mist, with straight water and FFOF. After that, I got me a ph pen and EC meter and started feeding nutes. THATS WHEN THINGS WENT AWRY. I started seeing burn and other tell tale signs of bad things.
With that being said, I have reverted back to using tap water and FFOF myself for a while now (3 years) and have had great results. What I do is germ seeds in rapid rooters, veg in a small pot of ffof for about 28 to 30 days depending on the rate of growth. After the 30 days are up, I'll up pot them into 3 gallon bags with new FFOF and flower them immediately. Set it and forget it.
Side Note: I do keep nutes on hand just in case, but unless the plant is telling you that she needs something, i wouldnt worry about them. And Im speaking on experience