You can see my attempts to bring my deep water beds under control after my computer irrigation pH meter fiasco. I have since re-calibrated it and it should be good, but I’ll be monitoring it by hand more astutely from now on. (I hope it only takes one major crop disaster to learn a lesson like this).
In any case, you can see the adjustments taking place above. I’m not sure what happened in Bed 4. I have it recorded as only slightly more acid added than in bed 5. The water level was lower. I thought I was very careful, recording between each adjustment, but it’s possible I adjusted it twice. I’m not sure what else could have caused that huge fluctuation.
I see that I had a similar problem in bed 3, day 36. I didn’t mark it red, though I should as pH 5.5 is probably enough to damage the roots. I have added some pH high water to that bed, so I will check it tomorrow and see how close I got to fixing it. Hopefully it is fast enough.
It’s possible that the biocarbonates are less in some of the beds than others as I find the municipal water fluctuates quite a bit (which I notice when I periodically send in samples to the lab). I don’t currently, regularly measure this, but I will order some hardness test paper which will hopefully give me a sense of the biocarbonates in each bed as well. Hopefully that will help me gauge how much acid to add when I have to manually adjust again in the future.