ph to high and yellow leaves help

ok i am in the second week of flowering and the ph of my soil is just below 8 even though i water them with water thats at 6.5 soil how do i get this down?

also ive noticed that the very tips of the TOP leaves are turning yellow.

they are in canna terra soil(has nutes). they got fed with canna flores ( 1st time) about 4days ago

please help i dont wantto lose any more o my babies
 

nick17gar

Well-Known Member
8 pH is very high. id flush the soil, use a LOT of water. 3x the pot size... make sure the drainage is good. once youve flushed, add in water thats 6.5 and check the pH of the runoff, or by doing a slurry test (get about 1/4th cup of soil, 3/4ths cup of 7ph water, stir, let it sit for an hour, then test the pH).
start using something to get that pH down.

Top leaves turning yellowing, and any other issues right now are likely a deficiency, not becuase you dont have the nutrients in the soil, but because the pH is so high that the roots say no ty, and dont take anything in.
 
yes im going to flush them but that doesnt answer my question as to
WHY the ph is so high when the water is 6.5 and with nutes is 5.5 but the soil remains at 8?
also the soil ha been this high the whole grow cycle
 
What's up Bluedragon? I'm having the same exact issues on my first grow. I corrected it by getting some aluminum sulfate from the garden section at Lowe's and adding about a 1 1/2 cup to the soil and mixing before watering. I have had to do this twice in 3 weeks. All of the yellowing on the tips has gone away and now that I'm starting my third week of flower, things are completely back on track with coloring and other signs. My PH was at a solid 8 and now it's at about a 6.7(ish). I anticipate to have to add some more sulfate in the future but no complaints here. We have hard water which is why ours is so high.
 

Jack Harer

Well-Known Member
Flushing the soil is going to do nothing to change the pH of the soil. The media itself is slightly alkaline. Add a couple of inches of either peat, or compost, or both to acidify it. Even at 8, I doubt you;re in a lock out situation. You could be slightly overfeeding if the tips of new growth are browning.
If you want to lower the pH immediately, add a tbsp of sulphur, or as has been recommended, aluminum sulphate (nursery or garden center) to the top of the soil (sprinkled over) and water that in. What ever you use, take it slowly. pH can swing really quick.
 
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