Indoor Hello.....me again!

[Waira]

...could be Vapo,' both pH and ppm's... Ca-Mg will bump EC quite a bit, one reason why some folks use low ppm water to start with. Gotta leave ppm room for other things!
Ca-Mg is best put in first, (Si before even that if used, to avoid cross reactions of the Si with stuff in solution already; ditto for Ca++ too),... this helps buffer the acidity that most base nutes have.
BTW, if you suspect the EC meter is off, buy a calibration soln. for it... just see what the manufacturer recommends

 

[Vapo]

...could be Vapo,' both pH and ppm's... Ca-Mg will bump EC quite a bit, one reason why some folks use low ppm water to start with. Gotta leave ppm room for other things!
Ca-Mg is best put in first, (Si before even that if used, to avoid cross reactions of the Si with stuff in solution already; ditto for Ca++ too),... this helps buffer the acidity that most base nutes have.
BTW, if you suspect the EC meter is off, buy a calibration soln. for it... just see what the manufacturer recommends

Got and calibrated before use dude, Buddhas Tree recommendation is 3 ml A+B per litre of water....but start of the 4th week of bloom you change up the nutes and introduce Meta Boost again and PK 9/18 is slowly introduced too on that week.....but to compensate they bump the A+B up to 4 ml per litre....?......I have dialled back the A+B to 2ml per litre and they seem much happier with an EC 1.6 reading.....thanks dude