Fabric pot changes PH?!

First of all, don't test the soil - test the water or nutrient solution you're giving her and test the runoff... I'm afraid 3 weeks ago, you took the advice of someone who really doesn't know what they're doing or how to explain things very well... First of all, you are growing an autoflower and they cannot tolerate such high EC or ppm as either he told you or you are giving. For her age, your ppm should be at or near 600 (this will give an EC of about 1.2). Since you've been overfeeding this one and having wild swings in your pH, you've now got a nutrient lockout going and you are going to have to flush. For you, growing in an 8L pot, this means you need to take 24L of water that has been pH'd to 6.2 and run the entire amount through your plant... do this in one sitting... then measure the pH of the final runoff.. That should now measure 6.2 - if it still reads high, run more pH'd water through her until the runoff gets to 6.2pH. Then run a final liter through her pH'd to 6.2 with the amount of nutes that will give you a ppm reading of 300 (always add the nutes to the water before adjusting the pH). Then sit back and let her dry out completely. When you next feed her, bring your ppm up to 600 - but don't go past that reading. Autoflowers don't tolerate high levels of nutes the way photoperiods can and do. The nutes will need to be good bloom nutes with lots of P/K in them - I would cut the Bio Grow nutes to 1/4 of what you're giving now ... they're not in veg, they're in flower and they don't need as much nitrogen as they did in veg... This will all work out... it really will. Don't worry about the leaves that are now turning yellow - trim them off so they don't bother you visually and you can concentrate on making sure the rest of the plant is good going forward... And fabric pots are actually VERY good for growing weed... and no, they don't affect the pH readings at all Good luck...