Nute burn or deficiency

Jun 24, 2021
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Hi I have been following Tangs feeding schedule and have been feeding at 800 - 1000 ppm every 4-5 days. I also supplement calmag at 1- 2ml per litre per feed. I am growing in sungro black gold feeding bloom yellow Euro A&B.
11 - 7.2 - 18.8


Am I looking at nute burn or deficiency. Im at about the 5th week of flower and I have a huge gnat problem.
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The tips tell me you have too much nitrogen and the brown spots in the middle of the leaves could be Cal-mag deficiency. But then you say you have a huge gnat problem. Gnat larvae feed on the roots. But no pH given.
Maybe do a runoff pH check.
There are two parts to these instructions, look at the editor's part before you follow the initial advice:
"Measuring the pH of soil / soilless runoff

How to test the pH of your soil mix

The pH of soil is just as important as with hydro applications, but few people know how to test soil pH to see if it is within the optimum range for growing robust healthy plants. Here I will try to explain my method of testing any soil / soilless mix, enabling me to spot any problems and correct them if necessary.

Firstly, wait till your soil has dried out and is due for its next watering schedule. Then take some plain water that you usually water your garden with, and adjust the pH to 7.0. You must make sure that you know the exact pH of the water going into your soil, and the neutral 7.0 is best, but anywhere from 6.5 – 7.0 will suffice.
Then place your pot into a bowl of some sort to catch the runoff water, and then start to water your soil slowly (with your pH- corrected plain water) till the water starts to drip from the bottom. It’s the first drops of water that will give you the best reading of your soil, so make sure to water slowly till you see the first droplets. Then remove the pot from the bowl to eliminate excess water entering the bowl. Then perform the pH test on the runoff and compare it too your initial test.

The results of the runoff test will likely be lower than your starting value of 7.0. If this is the case, a small drop of 0.5 pH to 6.5 pH (example) would be ok and your soil needs no further alterations at the moment. But that’s not to say that it won’t need any future tests at all, just not at this time.
[Editor’s note: It may be beneficial to obtain an initial sample, as well as a ‘full flush’ sample in seperate bowls. In addition, test several plants in the garden just to verify your results]
What if the pH is off?
If your results prove to have dropped considerably, say to around 5.5 (which can happen in late stages of flowering), you will need to add some lime into your soil to help buffer the pH back up again.

Remove the first inch or so of soil, taking care not to damage any roots whilst performing this taskEnsuring that your pH is correct should be done throughout the life cycle; this will help eliminate any nutrient lockout that may occur. I recommend doing this once a month just to keep the PH in check, and you should never have a problem with deficiencies caused by pH lockout.
. Then sprinkle the lime into the pot, nice and evenly at a rate of 1 teaspoon (5 ml) of lime per gallon of soil. Then replace the soil you removed earlier, and saturate the soil good to wash in the lime.

Do the same test next time your plants need watering just to check that everything is fine, if more lime needs to be added then just repeat the process again till you reach close to 6.5 – 7.0 with the runoff.
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You are getting locked-out from too much fertilizer.
Will flushing help? How long till the plant is healthy again?
I know many peeps have had luck with Tangs method but it goes against the balanced nutrient approach I believe in. So in that regard I do not know what to do to help you.

This is the nutrient approach I use and believe in. Read it and see what you think.