Low PH brown spots

Alaskan1

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Hi All, :tiphat:
This is my third grow. Last two times were Lowryder 2 (find my earlier grow journal), and this one is Lowberry and auto AK47. I'm hoping for some seeds. I'm crossing the male Lowberry with a female Lowberry and with an auto AK47.

Last grows were in Sunshine Mix #1, and in this one, half were in FoxFarm Ocean Forest and half in Sunshine Mix #1.

So here's the deal, I water with PH balanced water and later with PH balanced light nutes (Fox Farm Grow Big and later Fox Farm Big Bloom). But after 5 weeks, the brown spots set in, and I check the runoff, and it's always low ph. So then I have to flush, flush, flush, to get the PH back to healthy levels.

I check every watering, and it's PH 6.5, but after 5 weeks the PH is in the 5s.

Oh, and the Fox Farm soil is even lower PH than the Sunshine Mix #1.

Will I always have to flush half way through to adjust the PH higher?

Thanks!
 
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Do you water enough to get about 20% runoff each time you water? Maybe you're getting salt build up in the soil. Watering enough for a generous runoff can help avoid that problem.

If flushing fixes it, that's probably what it is. But, dolomite lime can help too. A lot of people add 1 tbsp dolomite lime per gallon of soil.
 
Agree with az. Also your soil when you mix it, how long do you let it sit before popping a seed or seedling in there?
 
Thanks for the replies. I don't let my soil sit, but just fill the container with either of the two mixes, then dig a small hole and place seed starting mix in the middle. The seed pops in the starter mix, and roots spread throughout after that. The Fox Farm and Sunshine mix state that it's ready to use, so why does the PH drop so, I wonder? I do let some run off go each watering, but probably not 20%. I guess I'd rather flush once than have to add lime, and figure the dosage of that. Seems like the bagged mixes would have taken this all into account.

So does anyone else experience this PH drop? Or is it just me???
 
So does anyone else experience this PH drop? Or is it just me???

I'm suffering a bad case of ph drop for the past 10 days or so. Flushing didn't fix it. It's more a problem with my soil.

Regarding dolomite: It's not uncommon for people to add it to name-brand products. There is a common belief that not enough is added by the manufacturers to get through an entire grow. I've read this regarding Pro-Mix, and alot of users who say they add 1 Tbsp/gal.

You could google about the products you use and see if it has a reputation where others supplement with dolomite.

If flushing fixed your problem, I doubt you need dolomite. It sounds like salt buildup, not enough runoff during waterings. Maybe a different nutrient would produce less salt. (Or, give more runoff or live with one-time flush).
 
You got any pics? And have you tried tying it down to a deficiency before addressing PH problem?
 
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