Alright here we go!
@TheMadDabber
I basically run a 4 bottle system for feeding. Cal-mag (1-0-0), GH Micro (5-0-1), GH Bloom (0-5-4) and GH Grow (2-1-6). If you look on most nutrients that run a two part system you have a part A and a part B. From what I've seen the Part A is usually the Cal-mag and Nitrogen together and the Part B is the Phosphorous and Potassium. Either way these 4 nutrients are what I call "Major" nutrients. Everything else the plant needs I consider trace minerals (zinc, iron, copper, etc.). The only thing I really focus on is the Major nutrients. I like to think that if you are following the instructions on a bottle then you are basically growing with something like the Lucas Formula. Lucas Formula is a very basic feed schedule and will get your plants through a grow. They won't be great but it will work. Basically you use the same single NPK ratio in veg and then use the same ratio in flower. There never are boosts in anything. Nutrients companies try to make it as easy as possible for customers because nutrients are confusing! The simpler the feed schedule is, the higher chance someone will buy it. Do not get fooled into thinking the nutrient companies are there to help you and are just making it easy for you to grow awesome bud. It's way too basic.
In the end the part that matters most to me is PPM, or parts per million. This is how much you are feeding your plants. If I say to do 500 ppm and you do 1000 ppm than you are overfeeding and the plants will likely have nute burn or you'll see a lot of salt buildup (likely a combo of both). The plants just don't need to eat that much and they take what their maximum is of the nutrient and the rest drains out the bottom. The maximum of a nutrient is not what you want because that is when plants will lock out and stop absorbing nutrients altogether until it can clear through the build up. IN COCO I DO NOT EVER WASH WITH PLAIN WATER UNTIL FLUSHING. If my schedule calls for 800 ppm and the plant is locking out then I will give it a very heavy feeding of 1-1-1 NPK solution and about half the PPM called for. It allows the plant to absorb some of the nutrients that it is heavy on (because the PPMs are lower) and also flushes it out (like a plain water flush). In it's place it leaves a very balanced NPK solution and the plant can start taking whatever it needs to fix itself because there are equal parts of all 3.
With all that said, basically the PPM is how much it needs to eat. That is what the feed needs to equal in the end. If I am eating a burger and fries then at the end I come out about clean at the same time of both and feel fine. If I get two burgers and just one fry then I always finish the fries too fast and am left with too much burger. If I get two burgers and two fries then my ratios are back to being the same but I am left with extra burgers and fries in the end. If I do eat the whole meal I tent to feel like crap because I am stuffed and I no longer want burgers and fries for a few days. I'm "locked out" at that point and refuse to put anything like it in my body for a while. If the next day someone says, "Hey I got you one burger and one fry because I know its the ratio you like" I'd still say I don't want it because I was overloaded from before. The PPM is how much you eat and you don't want the plant to feel stuffed or hungry. The NPK ratios are what makes up that total meal. If I just had 3 burgers instead of a burger, fries and soda than I most likely wont feel like I ate a balanced, fulfilling meal. I may have ate the right amount for my size (PPMS) but I'm not real thrilled with just eating one thing. Do that a few times in a row and now I feel sick and don't want anything. There are times I might want more fries or more burgers but since my feed schedule changes weekly, It allows for that. In veg the plants really like Nitrogen and calcium more than anything but the NPK is pretty close to 1-1-1 throughout the whole thing. In flower the ratios start to get much more drastic. As the girls get bigger you give them a PK boost and they go to town. It's like they are pregnant. They used to eat a burger, fries and a soda. Now they want two burgers, a fry and soda. Not only does their total feed (PPM) increase but their ratio mix changes as well.
I could calculate everything by PPM if my bottles were all of one nutrient. Each bottle has a blend of all 3 of the major nutrients so that makes it quite difficult. If I needed to hit a ratio of 1100 ppm and 1-1-1 NPK and each one was it's own bottle I could do 200 PPM of calmag (what I always do), 300 of nitrogen, 300 of phosphorous and 300 of potassium. This is the reason I I use ML to figure out the NPK ratios. If I have a bottle that is 5-0-1 then I have to account for each of the 3 major nutrients and PPM doesn't do that. Think of those numbers as parts. If I have 1 gallon of water and I put in 1 ML of micro than I have just put in 5 parts nitrogen, zero phosphorous and 1 potassium. It might equal 100ppm. If I do it again I will likely be at 200 ppm and my NPK ratio is now 10-0-2. I then have to add up my micro, bloom and grow and then divide them by a common number to get the exact ratio of what I've put into the bucket of all 3.
This is where using different nutrients can be tricky. Nutrients aren't standardized and come in all sorts of different shapes and sizes. I noticed sensi's nutrients in flower are 3-0-0 for part A and 2-4-8 for part B. There is no way to achieve my ratios with just the basics of of sensi in my opinion. You'll get good stuff but it won't be ideal. That is why sensi has all the other stuff in line for boosters. Because it isn't all inclusive in just the basic bottles. You can use the same math when you add in boosters to you core products and get a total N-P-K. Usually its the core ones that make the biggest difference but ML/Gallon gives me the right ratios and I just have to work within that to get total ppms. If I overdo it I can just add water and dilute it a bit and NPK ratios stay the same and the PPM drops and that's how you can get to the right combo if it's too high.
Hope it helps!
1 when I add my other nutes, and then as I add those nutes I'll measure to see the PPM impact. I know my ratio will be dead on. If my PPM is off, I can use the same ratio but in different amounts the next day to keep the ratio but fix the ratio.
