When Growing any plant PH is a important factor. The PH scale starts at 0 (acidic) to 14 (alkaline) Cannabis requires when growing in soil 6.5 PH and when growing Hydroponic it should be 5.5-5.9 having a accurate PH helps the plant uptake the nutrients it needs if the PH is not correct it locks out nutrients. I use the liquid General Hydroponics PH up and down and a Digital PH meter to test the PH before adding water or nutrient solution to the soil or reservoir, gradually use one drop per gallon as it is very concentrated and needs a tiny amount to move the PH. You an also buy PH up and down in the powder form. You should also weekly test the run off (draining water) from the plant pots to make sure its 6.5 If not adjust it correctly.
TDS and EC
TDS is the total dissolved solids in your nutrient solution its measured PPM – parts per million. EC is the Electrical Conductivity that the PPM meter reads, always test the nutrient solution before adding it to plants newly sprouted seeds need a lower PPM around 100. As it starts growing in vegetative I raise the levels it can go up to about 700 depending on how big the plant is. In the later flowering stages its much higher around 800-1500 PPM depending on how far along the flowering stage is. Each week raise it little by little and every 2-3 weeks flush out the soil with a flush solution to rinse out nutrient build up also flush out before the flowering stage. In flowering 1200 PPM is ideal in the later stages each strain is different. Its best to use Reverse Osmosis water for Cannabis growing because the level is at 0 or is low so it leaves room to add the nutrients so the plants don’t get too much salts built up. In the flush out stages it shouldn’t go over 100 PPM in the water your using to Flush.
If you have any questions feel free to ask Thank you for reading.