PH levels?

pH problems can potentially cause any and all nutrient deficiencies and toxicities.. so, kinda imporant. Soil is more forgiving due to its microbial content. If you have RO, you are probably fine without ever checking or a second thought about it. Although your fertilizer could be a problem if extremely acidic when added to RO as opposed to a ~8.0-8.4 alkaline tap water you typically see. Some ferts are actually expecting you to use that 8-8.4 instead of 7, which would potentially result in a very acidic irrigation. It's just chemistry. At various pH levels the plant's bio-chemistry simply won't work. Just like if you start pounding water you will die from hyperhydrolosis. your body's chemistry will simply fail to work - due to concentrations rather than pH but same fundamental concept. a plant's processes require a range of temps, pH, pressure, etc... all are important, but usually you don't have to worry about many at one time. pH strips are cheap and can resolve down to .1 pH, which is more than good enough. Get 100 for $7 on amazon. Test your water.. if city water it'll be consistent. If well water, you probably want to test occasionally and especially after heavy rains. Know what your ferts do to pH too... after a while, you won't have to test at all. The familiarity you gain will be enough. measure and be consistent. it'll always balance out the same because it's math/physics/chemistry = reality.