PH Drift....why?

I had the same issue continually so I switched to soil..problem solved...but some people said it was the airstone, because after a years worth of use I highly doubted it was the Hydroton...Could never get the Ph to stay below 8

I do dwc and my ph is 5.8/6 is the highest it goes.
I use hydroton and some air stones can do that to the ph.

I use a Milwaukee ph600, which is probably what 80% or more of us use, due to it's sub-$20 price and ease of use. I have discovered that at least some of what seemed to be ph drift was actually drift in my meter's calibration. The weird ph movement I've been seeing lately (see the original post in this thread) really made me question the meter. Eureka! I ordered some ph 7.0 reference solution, and the meter was off by about .8! So, I calibrated it and re-checked the reservoirs. Lo and behold, both rez's were down around 5.5. I'm just lucky I didn't fry my girls due to an uncalibrated meter. Yes, you have to wash your Hydroton thoroughly, but you also have to be able to trust your measurements. The basics:

1. Keep the probe damp - a small piece of paper towel or sponge wetted with 7.0 reference solution inside the cap takes care of that.
2. Keep it clean - rinse the probe with distilled water often, preferably before/after each use.
3. Keep it calibrated - check it daily, IMO.

I now know that the two major issues I've had here were at least partially due to poor meter maintenance.

And just a footnote: if your meter is dirty/uncalibrated, the error isn't linear, ie always .5 high. It's unstable, giving you a varying error that can drive you crazy and cause you to harm your plants.

OK, I'm a noob and I'm sure this has been covered elsewhere; I just wanted to leave a note in this thread for anyone else who may be getting run astray by their meter.

Ciao!

Right on, Flash. Meter calibration is probably one of the last things to be recognized. I have found that Coca Cola ph'es out at a consistent 2.4, and since I drink gallons of that shit, it's always at hand, so I use that for calibration. I do not suggest this to anyone else as a calibrant, just sayn. Good catch Flash.

Glad to hear you found your problem.

To be honest I didn't think to ask about your meter.

I calibrate mine approx every 5 days.

Costs me a fortune in 7 and 4 solutions lol.

If your pH meter has a protective cap, I use this cap to leave 7 solution in so that when I close my meter it sits in the 7.


Sometimes the simple things get forgotten about when troubleshooting.



If you want a good meter then the BLUELAB PH METER is good.

My meter is a SUBOTA or something to that effect. It has replaceable probes and it cost me £40 approx $70.





J

First time growing is like Whack-A-Mole - every time you beat a problem, a new one pops up. You just gotta keep Whackin!