PH

What is a good PH for soil?

6-7. I prefer 6.4, but every few feedings I go up and/or down a couple of points to ensure widest nutrient uptake.

-spek

Yeah makes sense, another reason I was wondering is because someone had said in dirt that as soon as the water goes in the dirt it automatically drops a couple/few points so was just tryin to get an idea from others perspective cause every damn book I read says different shit

What type of soil mix are you using? Some will have a very neutral PH. My run off doesn't change much going through the soil.

The RO water I use drops when I add my nutes in and I need very ph down at that point

AKHUNTER said:

someone had said in dirt that as soon as the water goes in the dirt it automatically drops a couple/few points

Click to expand...

That's true, but I wouldn't say it that way. Soil ph rises as it dries. That's why overwatering is a problem besides fostering unhealthy things like root rot: it holds low the ph range which the plant will experience in proper wet/dry cycle.

I have a $60 Control Wizard Accurate 8 soil probe. Soil probes aren't hugely accurate, but it's better than those $10 probes at retail stores. When I water it drops to 5.6 and will rise to 6.8 when time to water.

I'm not sure a soil has a PH. I think it interacts with water. If water has a lot of ppm and/or ph buffers, it will counteract the soil ingredient's pull (usually downward as salts accumulate, dolomite lime is exhausted).

The most "official" (legitimate?) way to measure soil ph is the NCSU Pour-Thru Method (google for it). This involves letting water sit in the medium for an hour, equalizing to the soil's effects (and the soil equalizing to the water's, if it is buffered, etc.). Then adding just enough water to displace a measurable amount of runoff (so as not to dilute this equalized liquid with newly added liquid).

I measure runoff and use the probe. Doing this for awhile has given me a feel for how to interpret my runoff values. I kind of know how long I let the water saturate before pouring more for runoff. And, how much the runoff might be diluted by the new pour. I know that a 6.1 value really means 5.6 if I'd given it an hour to saturate, small (undiluted) runoff, etc.

I think measuring runoff and probing soil is mostly a waste of time if you have your nutrients and soil working. But, I think they're really valuable when changing nutes or soil. I like to see trends in these values (and PPM of runoff) when a problem occurs. Not the values when the problem occurs (because the value by itself isn't too accurate), but the trend leading up to the problem.

I think all this ph stuff is overcomplication, if you mix your nutes proper you can attain the perfect ph every time without having to pull out the meter. I know that some would frown upon this but if A. doesn't change and B. doesn't change then C. should remain the same.