leaves yellowing

[9fingerleafs]

thats why i went coco and never looked back, i got control over the ph, the nutrient ratio and concentration. no more issues

[JohnEmad]

yup 9fingers. many lessons to be learned. So far nothing real dramatic like seeing all my plants die when nearing harvest...or something crazy like that.

[9fingerleafs]

the thing about dolomite is that it behaves as a buffer, it will continue to pull ph back to 8+ for ever, you may have used too much in the initial mix, next time i would stay way from it.

[JohnEmad]

I tend to agree. Been fine from the beginning but flowering seems to have different demands and I may have to ph all my h20 at 6.0 or so to compensate

[9fingerleafs]

i think the problem may be the dolomite as it has a very high ph

[JohnEmad]

Hi everyone. need some help diagnosing the yellowing leaves on all 3 of my plants.
Growing in soil. 3rd week into flowering. Using town tap water and filtered water from an outside vendor, The town water is hard and I have tested it between 7.3 to 7.9 ph so have used as is.
The vendors water was filtered in reverse osmosis process and remineralized with a ph always set at 7.0 to 7.5 according to vendor. I tested it after signs of yellowing to find the water very high at 8.4 ph.
After reading up I am thinking the plants are ph locked causing a deficiency in iron, zinc and magnesium.
I decided to flush with water ph'd at 6.0 to see what comes out of the pots. collected water tested at 6.5 to 7.2 depending on the pot.
Did a second flush 2 days later with h20 set at 5.9 ph and collected water measurered between 7.2 and 7.5 ph. so appears high ph may be the problem.
No nutes being used as it caused tip burn the few times I added even very weak nutrients. Soil has dolomite lime added to counteract the peat. Tested the soil at the beginning of the grow to 6.2 to 7.0.
temp is at 68 F night/ 78 F days. RH runs 65percent nights and 50 percent days