I will hit the sky

microbes and such will set the pH in your soil, since they are constantly 'eating' and excreting. what we add to the soil is small in proportion to what the microbes are doing relative to resultingn pH. (ratio of H+ activity or easier to think of it as h30+:oh- ... at "6" there is 10x more h30. at "5" there is 100x more h3o, and so on. it makes the numbers so large on each side of ratio that when you add something else at much smaller proportions to total it doesn't have much impact... same way "buffering" works) 5.9 is within a safe range. Is that what you fed or a soil slurry/runoff? if it's what your fertilizer comes out at, i wouldn't worry too much about it... if things remain fairly consistent, you can adjust your fertilizer mix relative to naturally resulting pH. e.g. a slightly lower pH may require a bit more N than a slightly higher pH. These are things you need to figure out over time, regardless. Just try to be consistent - within reason. Soil microbes should take care of it. supposedly 6.5-6.8 is better for soil grows. think it has to do with using unchelated nutrients?

Hey buddy. The reading of 5.9 is the soils PH. even if you were to pour 6.5 in soil it would come out as 5.9. Soil is much more forgiving for high/swings in PH, And as this only happened once, it's really nothing to worry about at all. What is the normal PH u use. With soil been set for 5.9 you should be aiming for 6 to match it, just overall it's better for nute uptake in that range also. Even when I flushed my plant, cause I fed her the wrong mix by mistake and the soil is still 5.9 12 weeks later. Happy growing, good luck!

It will be fine, one mistake wont matter. Just carry on as if it never happened and check it in future first and you be fine.