Is AISI-302 stainless steel good for the reservoir with nutrients?

[SamandMax]

After removing CO2 and lowering temps (switching to external air) - plants sick?

You should have a healthy pH swing to allow the plant absorb all the nutrients it needs. Look at this chart, notice the range for hydroponics on the left is 5.5 - 6.1. So you’re locking out P and Mg. [image]

Why this graphic shows a completely different range for ph of potassium availability in hydro???