Stinkbud, do you still use the same nutes and strength for flowering? The recipe on pg 75 2000ppm and 5.8 ph or have you changed it and if so can you please repost it if its not the original one. Thanks
Your PPM is really strain dependent. I was reassured of this on my current batch. I have 20+ different strains going right now. I feed them all exactly the same nutes at the same strength. Some are showing signs of over-feeding, some are looking under-fed, most of them look perfect. I once had a strain called Snowbud that could handle almost 3000PPM! I've also had strains that show signs of over-feeding at 1200PPM. So which number is right? They both are...
Why is this so? Think about it for a second. Some plants ancestors originated in the rocky regions of Afghanistan (Kush region), where there are not much nutrients in the soil and overall it's pretty dry. Then there are Sativas that come from the tropical jungles of South America, Mexico and Thailand that have a lot of nutrients close to the surface and a wet humid climate. All these strains have adapted to their specific climate. I'm sure you all know about the whole Darwin thing...
So what should you set your PPM at? Start at 800PPM and go up from there. Or start at 2000 and go down from there. Either way you'll end up at the same place.
What do you look for? If the plants are light yellow then you need to up your PPM. If the plants are super dark green and the leaves are curling under then you need to drop the PPM.
Here is a old video of my room running 3000W of light and CO2. I was running 1750-1800 PPM and harvesting 20-27oz. every three weeks. If I had just ran Snowbud I could have run 2500PPM+ and harvested 2+lbs.
http://www.youtube.com/watch?v=JDT9Hoqno14
Notice the batch on the left are in the final stages of flush and ready to harvest. The center rack are the newest plants. Look at them and decide for yourself if they look healthy or not. The rack on the right is about 6 weeks into flower. Again look and decide if they look good or not. This is my classic receipt with nothing special added.
KISS - Keep It Simple Stoner!
Good luck buddy!