@EP3 I do not see a major problem in the picture you posted. Perhaps we need to see more pictures taken in regular daylight -turn off the grow lights.
Whenever you choose to mix and match nutrient vendors you are playing nutrient roulette. Most vendors do not list everything in their products (they are not required to do so by law) They want to keep the Secret Sauce to them selves. This makes it easy to get too much of something causing lock outs.
All nutrients need to be present in a fertigation (water with nutrients) in balance. If you fertigate with a single or couple of nutrients alone that is the definition of out of balance. You are washing away the balanced nutrients and presenting only the P-K to the roots. For example P-K booster fertigated alone. Too much K locks out K, Mg, Too much PO4 locks out Fe, Mn, Zn and Cu
Now lets look at how you do it right.
This chart is not in EC it is in weight. It demonstrates the Elemental weights to keep a nutrient solution in balance.
This represents a 6-1-4 NPK ratio to start with but we will use the numbers for demonstration. All of the weights above are expressed as a percentage of 1 liter of water. A liter weighs 1000 grams. The math will not be exact but close enough for what we are doing here. 1 ltr =1,000g *6.31% = N =63.1mg/l, P = 9.5 mg/l and K = 38.5 mg/l
Lets double the strength N = 126.2 P= 19.0 K = 77.0
ok triple N =189.3 P = 28.5 K = 115.5
4x strength N = 252.4 P = 38.0 K = 154.0 This line shows the balance in relation to the common solutions chart.
5x strength N = 315.5 P = 47.5 K = 192.0
Our Target shown in the common solutions chart is N 100-250 P 30-50 K 100-300 according to the common solutions chart as you can see by line 4x there is a balance in the ultimate for coco.
Now we want to do a PK boost to start flowering but we do not want the solution to get out of balance. Using line 4x we can add 12mg/l of P + 38 from the base nutrient = 50 and 146 mg/l of K + 154 from the base = 300 and still be in balance. So to use the base nutrient at regular strength You can add (12/4) 4mg/l Phosphorus and (146/4) 36.5mg/l of Potassium and your nutrients are in balance. This math applies to all of the elements not just NPK.
Does all of this seem too complicated.

Now you may understand why I reccommend people to use a single vendor for their nutrients and use the vendor's charts. They do all of this math and they know everything that is in their products including the Secret Sauce
