Optimal sun exposure?

You’re probably referring to me as part of those other growers. Definitely a learning process for me with this pH stuff.

They were high, now they have dropped to the lower end. I have managed to go thru each one, bringing runoff to 6.3-6.5 range, but I have my suspicions that i will get good runoff numbers next feed.

Could you help me with the process a little?
Before feeding, I want to do slurry tests to determine how to pH up or down. Is there a proper amount of soil:water and does the water need to be ph’d to a specific number first as I’ve read on various threads?

I’ve done slurry tests with soil a few inches down and regular tap water, gotten 6.5 only to feed with 6.5 and see runoff at 6-6.1. it’was a little confusing when that happened

The soil will absorb nutrients from the feed to the point where all of the absorption sites have been filled up and it no longer can absorb nutrients. If there is a change of pH from input to out put it means the soil has stronger ionic strength and is influencing the pH rather than the feed. At some point both will be in ionic equilibrium and the input will be equal to the flow through. If you are getting 6.1 means that your soil is controlling the pH.

A soil slurry allows for the complete exposure and measurement of the ions absorbed to the soil.

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thanks for the science - helps me understand the issue better. Could give me the specifics on the slurry process? just copy/pasting from the previous post so i dont start confusing the issue with rewording: Is there a proper amount of soil:water and does the water need to be ph’d to a specific number first as I’ve read on various threads? I’ve done slurry tests with soil a few inches down and regular tap water

ive read, from other growers, that you need X tbsp of soil and Y amount of water @ Z pH @ ∑ minutes
perhaps theres a standard?

Too many unknowns for a “simple“ formula but to make it simple it is best to reach a desired equilibrium pH in the soil with a feed that is higher or equal in ionic strength (simplistically PPM but it also needs to contain buffers such as phosphate or carbonate) to the soil @ the desired pH. You can also do it with a higher pH but you can overshoot on the high side and cause another problem. Once you have the correct pH you can lower the strength of your feed to where you want it. The more volume you wash through the soil does wash out the nutrition in the soil and replaces it with nutrition in your feed.

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Gotcha - so you’re suggesting to just continually feed at 6.5 until the soil finds its way there. If I want to speed that process up, shooting higher (or lower) to buffer soil pH to the desired levels, while not suggested, is possible - but I would need good pH data to be able to counter it in the feed.

I’ll go with the Hannah method for now. It seems like a reliable source on the matter.

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That method is for static testing and is very appropriate for formulating soil mixes prior to planting, but does not address the changes to the pH of the soil when you flow through nutes and water at changing strength and pH. Both methods require a reliable/calibrated pH meter

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I grow in full sun, plants love it, I grow in containers in the high 90 even 100 degrees, it looks like another issue than the sun. Get your ppms and ph check good luck my friend