He's showing signs of low pH and Coco Coir becomes acidic as it breaks down? Maybe you mean the other way around?I don’t understand everything that’s going on…has anyone checked his run-off pH? Just looking at pictures ….the pH seems to be high. I could be absolutely wrong, but it seems it’s creeping up having looked at the progression and looking at the pH numbers. I don’t know if the grower is in coco, lower than 6.0 pH would help A LOT.
Feeding lower than pH 6.0 in soilless is not very advisable. pH 6.5 has been the recommendations for decades but all the bad marketing and mixed hydro information makes new growers ignore the medium they are growing in and instead blindly following set recommendations(in this case pH lower than 6.0) instead of plant response.
You see these general recommendations for hydro and then new growers believes it to be gospel and copy paste the information. Coco coir and peat are both living mediums even though they're considered soilless/hydro and this needs to be taken in to consideration to know what optimal input pH actually is throughout the grow.