Is my tap water ok?

tomato57

Well-Known Member
I have worked with quite hard tap water on several of my previous grows and the plants responded well to it, only in the very end I have seen the detrimental effects - lockout of iron and other micro-nutrients due to high pH. Cannabis is generally pH tolerant but because the pH of my tap water was 8.4 and the alkalinity was high too the soil's buffers struggled in the end. If you are concerned that your water source is also strikingly hard then amend the soil or the irrigation water accordingly, or just get a brita-filter, reverse osmosis etc and mix the tap water with the filtered water to get an overall lower ppm.

good luck
 

meefeater

Active Member
I have worked with quite hard tap water on several of my previous grows and the plants responded well to it, only in the very end I have seen the detrimental effects - lockout of iron and other micro-nutrients due to high pH. Cannabis is generally pH tolerant but because the pH of my tap water was 8.4 and the alkalinity was high too the soil's buffers struggled in the end. If you are concerned that your water source is also strikingly hard then amend the soil or the irrigation water accordingly, or just get a brita-filter, reverse osmosis etc and mix the tap water with the filtered water to get an overall lower ppm.

good luck
Well if i adjust my tap's ph to just under neutral before every watering, add dolomite lime for buffer and monitor the soil ph, won't I be able to avoid the detrimental effects you experienced from the high ph of the water?
 

tomato57

Well-Known Member
It is unlikely that you will have any problems even if you don't adjust the irrigation water pH, which doesn't have much of an impact on the soil pH anyways (its more about the presence of carbonates or your fertilizer's Nitrogen form: ammonical nitrogen usually causes roots to exude H+ bringing pH down and Nitrate form does the opposite to soil pH over time). High water pH does not necessarily mean high alkalinity, but high alkalinity manifests itself with generally higher pH values. My point was that even though my water was very hard I had only very minor issues - cannabis plants tolerate a lot. IMO tap water and pH should be your least concern, especially with a well buffered soil, they rarely are the culprit of the issue.
 

donutpunched

Active Member
What Balze Master said! If you can drink the shit you can grow with it! After a year of using RO water.... I run straight out of the tap......
 

althor

Well-Known Member
Really depends on ph of the water and the soil. If you are using a soil with a low ph and water with high ph, or vice versa, you are fine.
I have water phd at 7. When I am using fox farms or like soil I use it unadjusted. If I am using something like sunshine mix, I will add ph down to lower the water to about 5.5.
 
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