Pale leaves with green veining

[Stone]

Fe

This all makes perfect sense. I am sure you are correct that finding the correct balance of nutrients in S/H is more challenging than in an organic medium. And I obviously haven't found it yet. I guess maybe that is part of the challenge, I want to try to figure it out. Perhaps someday I will throw in the towel and return to bark culture but I am not there yet. I will take another look at the micronutrients and also the ph and see if I can find something that should be tweaked.

In hydroponics Fe can be very unstable. The best is the FeEDDHA chelated iron because the FeEDTA breaks down quickly at pH values over 5.5. I would investigate if that is your problem - or part of it. Try lowering the pH of the solution to 5.5 to see if that helps or perhaps buy some of the Fe compound mentioned if you don't want to lower pH and try it on a few plants. You can begin to see how tricky this can be.. If that does not help you need to keep looking elsewhere. (the plant in the back of the first photo is in serious trouble).
Anyway, iron is usually the first thing to investigate if all nutrients are present and you are getting chlorosis in the newest leaves. It must be in balance with Mg, Cu and Zn. **Also check if sulphate-S is there in the Peters. Also, is the ''Cal Mag'' the one with Calcium chloride? Very bad!
Your tap water might be ok but I can't read it.

 

[CharlesD]

Agree with stone and gone wild. pH would be simplest place to start. It does look like you need to supplement Ca and Mg however. My well water has lower pH but still at 7. It has sufficient Ca and Mg so I can get away with 20-20-20 without Ca and Mg. The main reason I use this vs 30-10-10 is that the extra P lowers the pH of the solution to 6.3. I would suggest playing around with what pH you get with different fertilizer solutions then getting a pH lowering acid if needed. it’s also important to have sufficient buffering in solution you do add.

 

[Ray]

I don’t know what Lance is thinking, but 50 ppm TDS is hardly “high”.

Personally, I think you’re unnecessarily “forcing chemistry” on the plant. Between the Peters fertilizer and the water, they’re getting all the nutrients they need. I would double the Peter’s dosage and drop the rest.

I had something similar happen to a single phrag. I was experimenting with using rockwool and perlite as a medium, but did not acid-treat the rockwool before use, which has likely led to the rhizosphere pH being higher than I realized. Following Xavier’s advice, I started giving it the new formula of K-Lite that has 15% NH4-N, rather than 2% in the original. Within a few weeks it had greened up again. (That will be my preferred blend going forward.)

Nitrate-based fertilizers, over time, can lead to an increase in substrate pH, while ammonium-based ones can have the opposite effect. Merely changing the pH of the applied solution does not compensate for that. It is more the combination of medium + plant (some have their own nitrogen-form preferences) that affect that.

 

[gonewild]

I don’t know what Lance is thinking, but 50 ppm TDS is hardly “high”.

It's hard to read the analysis report on my phone but doesn't it list the TDS at 500?
If it is actually 50 then TDS is not a problem. However the pH is to high unless I read that wrong as well is it not 8.22?

Edit... I see now the 500 TDS reading is in the maximum column and the TD's is actually 54 ppm which is not a problem. But you need to know the ppm and pH of the fertilizer solution to diagnose the pale leaf problem.