Hello, I am using a coco fiber medium, which I've always heard is extremely pH friendly, and House and Garden nutrients in a top drip recirculating system. I mix my nute water, and adjust the pH before putting it into the reservoir. I changed the water yesterday, and when I checked it this morning the pH had risen from 5.7 to 6.8. I have no idea what would cause this.. any help would be great. Thanks!
What kind of water are you using? It could be because you have too much nutes in the water itself, what is your ppm count?
From what I have read, ph rise is a sign that your plants are consuming all the nutes. I would try raising the ppm of your water and you should see less ph rise. Too much nutes, and you will see ph drop.
when ph balancing your water let it sit for a while, like 20 mins after putting nutes, ph down etc... , then check what ph is... let the solution buffer a little.
if your not using reverse osmosis water the trace mineal levels can really screw with your ph levels. also as you water temp changes so will your potential for hydrogen (ph) so starting with your water close to or at the temp you keep it at should help. good luck
Not a big fan of coco for this reason. I'm using a hydro setup too, but another medium, with the pH Perfect technology from Advanced Nutrients - no pH problems here. Heck, even AN doesn't guarantee their pH Perfect nutes will work with coco - they're that testy. The medium, not the company. LOL Good luck!