PPM&EC levels.

So i have two plants going,ones a giant. I give them the same water nutrient use. Im getting random yellow leaves so i gave the plant a gallon of plain water to check what the EC&PPM levels in the run off water was&it was extremely high.PPM was like 2700 and the EC was in the 3s. I dont understand how thats possible. The other plants levels were high but still in the right range. I mix the nutes all together so the plants always get the same water except maybe a couple times. This plant grew too big and i just left it alone in the Soil/CoCo FF mix instead of transplanting so the whole 3 gallon pot is filled with basically roots so the water takes a while to go through whereas the other plants stilll loose soil-thats the only difference between the plants.
I wasnt sure what to do and read up on some things. I ended up giving the plant a florakleen flush to lower the EC levels. I am hoping everything stabilizes. I will give regular water tonight b4 i go to bed&go back to the nutes in tomorrows feed.
Do you guys think i made the right call with the florakleen?
These plants smell so good, the best ive had, Super Lemon Haze&Blue Dream. Strains smell delicious. Very citrusy flavorful. I dont want things to get worse this plant is 3+ months in the making.
Have any of you guys had success in lowering the EC levels with Florakleen?

Pics?
Sounds like your plants rootbound and or there's an issue within your medium. Diff plants feed diff ways. Some plants will feed heavy while others prefer a lower feed.
What do you mean you 'mix all the nutes together'?
What medium are you using
Wait soil coco and FF? Lol couldn't decide on one so f it use em all?

FoxFarm CoCo is a coco/soil mix. I have two plants that started flowering at the same time. Both plants are given the same water, I mix in a 1 1/2 gallon container,the big plant gets a gallon the smaller a half. One plant is blue dream the other is lemon haze. One plant is a monster,another is 3 foot.
I always check the runoff water to see if its coming out at around what ec&PPM levels i feed it. THe one smaller plant was a little high but in a good enough range, the other was extremely high. The PPM was high 2800 and the ec was 3200 when its supposed to be in between ppm 800-1000 or 900-1200 for a heavy nute mix and anywhere between 1.4 at the lowest to 2.3 at the highest.
I gave the florakleen mix this morning, Tonight i gave plain water and the PPM&EC levels went down a lot. I think i have it under control, just wanted to hear peoples experience in using Florakleen to lower levels when the plant is in mid flower.
I am praying i have it under control bc this is the best bud i have grown so far-just by the way it smells.. I have the plants on the one side of the room i sleep in lol, so it smells delicious in here.