Hello.. brief description of set up here Container: 2 gal Medium: coco coir Nutrients: general hydroponics Lights: 8, 23w cfl at 12,800 lumens Temp: 72 Airflow is created by a small fan constantly blowing on the plant Plant is about 7 inches tall and 1 month old today. Problems started with yellowing of bottom leaves about a week ago. My Initial reaction was to add nutrients because I felt I was a little too cautious with the extreme small amount of nutrients I was giving the plant, only every other week. Now that I've added some nutrients, my ph runoff is at 5, which is pretty low. I've heard that the ph in coco coir varies from its runoff. Regardless, since yesterday light tan colored marks have started appearing on my leaves. my research tells me it has to do with the ph fluctuation. I tried to flush multiple times with ph adjusted water to bring the runoff ph up but I think maybe now the coco coir ph is too high. I'm really messing this one up. Note: I test ph, on a budget, with a vial and drops. Any input welcome, thank you!
vial and drops work well, not super accurate but valid non the less. The reason you are seeing wild fluxuations is because the PH scale is not linear its logarithmic. You are swatting flies with a sledgehammer. A little trick is stop reading run off, just put perfect solution in and ignore the run off. The run off has you chasing your tail, that is like driving down the highway using only the rear view mirror to navigate.
Its should not be an issue. mix your soup/nutes/cal mag/ whatever then test the PH. Dont mix soup, test than add stuff. I have not tested PH this year and I have 16 5 gallon hydro plants growing.