Runoff testing around .5-.7 higher ph than water going in

Hey guys, just have a quick question. I am running FFOF amended with 1cup of dolomite to a 1.5cu ft bag. I have been noticing that my runoff ph is around .5-.7 higher than water going in.

Today for example, I watered in at 6.53ph / 155ppm (no nutes) and my runoff was sitting around 6.9-7.18 with about a 270ppm. I believe the dolomite is buffering the water as it passes through up to around 7ph. The increased PPM seems like the FFOF is just leaching out nutrients, so I am not too concerned with this. My actual soil ph tests between 6.3-6.6 on average for the past two weeks. I have always watered between 6.4-6.6ph.

Am I right to assume this is just the dolomite working and to not worry so long as my soil ph is staying in the sweet spot I mentioned above? If not, should I assume it is okay to water in at about .5 ph lower than usual to get this runoff into the prime ph range? Instead of 6.5ph, I would water in @ 6ph for example in hopes to see the runoff coming out around 6.5-6.6? Runoff confuses me because for every one person who says that is important, there is another person saying runoff PH doesn't matter that much if it isn't fluctuating very far off from the water-in ph.
 

lime73

Weed Modifier
You have it in appropriate range, long as its not a huge spike you have nothing to worry about.
 

xtsho

Well-Known Member
Just water normal pH and don't worry about the runoff. If the plants are healthy they won't stay that way if you keep trying to adjust the runoff pH by dumping low pH solution into the soil.

The people saying runoff pH is really important and that you need to adjust it by using high or low pH solutions are newer growers that don't understand the pH at the root zone is not what the runoff is. I've been growing for decades. The only time I check pH is when I mix nutrient solution. The growers dumping 5.0 pH because the runoff was higher than what they thought it should be are doing more harm than good and usually end up chasing their tail like a dog when they start having issues after going up and down with pH solutions trying to get the runoff to the perfect number they have in their mind.
 
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