pH runoff question

this is my first grow. i am growing 6 snowcap plants under 1000w hps. still looking at a few weeks until harvest.

we're growing in supersoil mix. i feed with earth juice at a pH of 6.5. yesterday when i watered i tested the pH of the runoff for the first time. the pH measured 8.5. everything on the internet seems to suggest that the runoff of the soil is typically lower than the pH of the nute solution. wondering if anyone knows why my runoff pH is so much higher.

also: i've been told that there is no point to flush when using organic nutrients--and pointless especially if using supersoil--but how long before harvest should i start feeding water-only?

thanks for the help

earthmama said:

this is my first grow. i am growing 6 snowcap plants under 1000w hps. still looking at a few weeks until harvest.

we're growing in supersoil mix. i feed with earth juice at a pH of 6.5. yesterday when i watered i tested the pH of the runoff for the first time. the pH measured 8.5. everything on the internet seems to suggest that the runoff of the soil is typically lower than the pH of the nute solution. wondering if anyone knows why my runoff pH is so much higher.

also: i've been told that there is no point to flush when using organic nutrients--and pointless especially if using supersoil--but how long before harvest should i start feeding water-only?

thanks for the help
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I say you have another 2-3 weeks more to go. I would start flushing regardless of what you are growing in after the 6th week into flower starting of 7th week. Some strains can be harvested a tad early at 6 weeks but that is more on a commercial growers knowledge with strain and technique etc. most are 8-10 weeks less it is a dominant sativa then it could take up to 4 months to flower! Again though, I think you should be good in the next 2-3 weeks, start checking the trichomes a week from when that picture was taken, they wont be ready but it'll give you a scale to start off with.

I grow in "Promix-HP" there is no nutrients in it or anything, its a "dead" soil, such as distilled water is, a "dead" medium to grow in.. zero ppm but carries a PH of more alkaline make up. So in soil seeing how you want the ph to be around 6.0-6.5 you need to balance it out. I balance my water/nutrients to 5.5 so that after drainage it buffers out around 6.5.

Most soil mixes with nutrients already in them etc. DO prove to be more acidic that is why the internet is saying that. I have no idea what ph the super soil is.. whether there is food in it or not, whether you are feeding when you water or are just using water but clearly you need to balance the ph of your water/nutrients lower to say 5.5, maybe lower i dono. Hopefully you get the idea tho.

Regardless of the ph, the plant looks fine lol. To lower the ph lower the waters ph like gibbs said