No, this is not untrue... this is absolutely true. Every plant has a threshold and if you cross the threshold your plants will suffer. Some strains thrive in a PH of 6.2 while others thrive at 6.5. If the PH is off there will be a noticeable effect on the plant. While soil is more "forgiving", the fact remains that, if the PH is not correctly balanced the plant will not be able to properly absorb nutrients. Just because you've never tested or adjusted the PH of your grows doesn't mean that it is unnecessary. It just means that you are lucky that your plants happen to thrive at the level your soil and solutions happen to be at. You have no idea what the PH of his tap water is in his municipality, so it is bad advice to tell him not to worry about it.
What you said was having PH off by even 1/10 of a point will effect your plants, this wont happen. Having PH off can cause problems, but you should not be adjusting unless your noticing stress, or if you have bad water to start with.
Also when I say not to worry about it I mean dont get all worried and paranoid that your plants are fuckd from having PH off by half a point. I clearly said to test the water to get a baseline. And if you actually read my post you would know I also said not to adjust unless they are showing stress.
If it aint broke dont fix it. Period.
Yes every plant has a threshold and every plant is different, but going around and telling people that having your water PH off by .1 or even .5 is going to fuck your plants is not such a great idea because then people think they need to adjust their PH constantly and the fact is, its going to be worse in the long run if your constantly adjusting PH. I didnt say I never have tested, I said I never need to adjust anymore for my SOIL grows.
Again, you should get a cheap water test kit and get a baseline for your waters PH then decide how much, If Any PH adjuster to use.
rola you should really read the whole post before making more claims.