Something I've found is that the 'recommended dosage' is way too high for my setup. My theory here is if you add more nutes, means you buy more of their product.
Like Frank, I've found my growth rate is better at between 1.2 to 1.5, anything much over 1.7 and I'm seeing a marked decline in plant health and that is despite the manufacturer recommending 1.8 to 2.0
Manufacturers often use the theory that we use tap water anyway. Tap water has already been treated (had chemicals added) to make it safe for human consumption. Rain water has an EC of 0. My treated tap water has an EC of around 0.7 to 0.9, even so I still only add nute to make the solution an EC of 1.2 to 1.5.
P.S. Young plants can show a decline if your salts are too high. I often explain it like this '...babies need to be nurtured, not beaten into submission. Start low'n'slow, then slowly increase...' Well, that's what I do.
Also here's a chart that shows how pH alters specific salt availability
Hope it helps
Edited by merl1n, 01 September 2020 - 03:45 PM.