Burpee PH Tester - Probe Depth and Accuracy

Howdy All. Big time newb here, first grow - but I thought this may be good info for other newbs. When I first bought this, it looked like I was getting readings that made sense, until I ended up with the beginning of nute burn about 2.5 weeks into flowering. Interesting story with good things to remember about the whole thing, but I'll keep it brief (unless someone wants the long version )

Found out that I was not using this tester properly. Was testing soil, and not always the full depth. What I learned is test runoff water PH (yeah, newb) and make sure probe depth is a full 3/4 deep in the runoff, otherwise your results will be inaccurate.

Runoff Water 1st Flush:

1/4 Probe Depth: 5.8 PH
1/2 Probe Depth: 5.0 PH
3/4 Probe Depth: 4.8 PH

Runoff Water 3rd Flush:

1/4 Probe Depth: 6.0 PH
1/2 Probe Depth: 5.4 PH
3/4 Probe Depth: 5.0 PH

Run0ff Water 5th Flush:

1/4 Probe Depth: 6.5 PH
1/2 Probe Depth: 6.2 PH
3/4 Probe Depth: 6.0 PH

I'll probably flush one more time, but I think the moral of this story is that one needs that full 3/4 depth for accuracy. Makes sense, after doing a bit more research - but didn't really see this type of info when searching here, so thought I would post up.

p.s. Thanks everyone for all the great info here.

So you believe that there is a salt build up because of the ph, or did you over feed. And Ph i not a scale to let you know when to feed.

RyanTheRhino said:

So you believe that there is a salt build up because of the ph, or did you over feed. And Ph i not a scale to let you know when to feed.

Click to expand...

I'm thinking a combination of salt build up and overfeeding before the flush. I'm going to back down on the feeding and be a little more careful about overfeeding. Figure I'll go back to feeding 1\week for 2 weeks, flush, one final feeding prior to harvest. Thinking it's about 4 weeks til harvest. Learning, Learning. Plant still looks very good with many bud sites, looks like I caught it in time.