K , Cal/Mag you are lock Locked.
Any Chemical/Organic nutrients that have potassium in them will fix a potassium deficiency. Peters All Purpose plant food 20-20-20, will cure the potassium deficiency , Miracle grow Tomato plant food, Miracle grow All purpose plant food.( Only mixing at ½ strength when using chemical nutrients, or it will cause nutrient burn!) Some other supplements of potassium are: Wood ashes, which are fast absorption, Kelp Meal, which is medium absorption, Greensand, which is slow absorption, granite dust, which is slow absorption. Sulfate of Potash, Sulfate of Potash Magnesia, Muriate of Potash, which are medium absorption. FOXFARM GROW BIG HYDROPONIC CONCENTRATE, which is fast absorption. (FFGB can bring your ph down as well) Earth Juice Meta-K, which is fast acting. (Can bring down your ph as well) Leaves will never recover, but the plant will show recovery after about 4 to 5 days when using a fast acting nutrient.
Any Chemical/Organic nutrients that have Magnesium in them will fix a Magnesium deficiency. (Only mixing at ½ strength when using chemical nutrients or it will cause nutrient burn!)
Other nutrients that have magnesium in them are: Epsom salts, which is fast absorption. Dolomite lime and or garden lime (same thing just called different) which is slow absorption. Sulfate of Potash, Magnesia which is medium absorption. Worm Castings, which is slow absorption. Crabshell which is slow absorption. Earth Juice Mircoblast, which is fast acting. (a must buy!! Has lots of 2ndary nutrients).
Now if you added to much chemical nutrients and or organics,( which is hard to burn your plants when using organics) You need to Flush the soil with plain water. You need to use 2 times as much water as the size of the pot, for example: If you have a 5 gallon pot and need to flush it, you need to use 10 gallons of water to rinse out the soil good enough to get rid of excessive nutrients.
To fix a calcium deficiency you can treat by foliar feeding with one teaspoon of dolomite lime or Garden lime per quart of water, Or Any Chemical/Organic nutrients that have Calcium in them will fix a Calcium deficiency. (Only mixing at ½ strength when using chemical nutrients or it will cause nutrient burn!)
Or you can take crushed up dolomite lime or garden lime in a gallon of water and water it in the soil. 1 to 2 teaspoons per gallon of water, which will be slow acting. Garden Gypsum, which is medium absorption. Limestone, which is medium absorption, Rock Phosphate and Animal wastes which are both medium/slow absorption. Note: Caution when using gypsum to an already acid soil (pH that is less than 5.5) can have a very bad effect on different types of plants by effecting the absorption of soil aluminum, which is poison to plant roots.

whatever you do better get on it. 5 weeks in that hurts....
Bloomin Idiot Reviewed by Bloomin Idiot on . 5 weeks into flower and having issues. PLEASE HELP!! This is a DWC grow w/5 gallon buckets. I've had pretty good luck up until now. I recently discovered my PH meter needed calibration, my babies were @4.8ish for over a week. I immediately flushed and went back to the 1000ppm GH 3part they had before. I saw signs of nutrient burn instantly so 3 days later I flushed again and went down to 600ppm. It's been close to a week now and the leaves continue to spot,turn brown, and die. Nutrients continue to increase and PH is still drifting lower. The Rating: 5