Runoff PH at 4.0

Hey guys,

I'm kinda confused now. I checked the PH of my runoff and it was at 4.0, then I flushed them with about 4x or more of the volume of water that the pot can hold with Reverse Osmosis water that was PH'd to 6.5. Checked runoff and it was still at 4.0

Then I poured in some water with a higher PH at like 9.0 and the runoff was still 4.0

What am I missing here? Is my runoff supposed to be in the 6-7 range? I am soiless. If so, how the hell do I get my runoff to test in that range?

Gonna bump this once. Any help appreciated.

Must have a ton of acid in there. Try bumping up to even higher PH to water with. Water with 8.0 PH until you get runoff at 6.0 or higher, then flush 1 more time with nutes and 6.5 PH.

Before you do this, if your plant doesn't look horible, double check your PH with another meter or method (chemical test).

nomofatum said:

Must have a ton of acid in there. Try bumping up to even higher PH to water with. Water with 8.0 PH until you get runoff at 6.0 or higher, then flush 1 more time with nutes and 6.5 PH.

Before you do this, if your plant doesn't look horible, double check your PH with another meter or method (chemical test).

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Yeah, gonna do that. I have the 4.0 and 7.0 calibration solution on the way already to make sure my meter is accurate, but I've also been using the solution tests and it seems accurate. I'll flush again tomorrow and see what the PH of the runoff is.

What soil? What nutes? What stage of growth?

If you have any milk on hand you can ph it. Should be around 6.7. This will tell you if your meter is grossly out of calibration. (If it's just +/-0.3 then I'd trust its readings and wait for your calibration solution.).

az2000 said:

What soil? What nutes? What stage of growth?

If you have any milk on hand you can ph it. Should be around 6.7. This will tell you if your meter is grossly out of calibration. (If it's just +/-0.3 then I'd trust its readings and wait for your calibration solution.).

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Pro mix, Botanicaire nutes (been going by the bottle dosages), 7 weeks veg. Right now it seems I have a magnesium deficiency, but I have been using Cal-Mag. I'm just thinking if my PH is out of whack they may not have been absorbing the nutes.

Coppertop87 said:

Pro mix, Botanicaire nutes (been going by the bottle dosages), 7 weeks veg. Right now it seems I have a magnesium deficiency, but I have been using Cal-Mag. I'm just thinking if my PH is out of whack they may not have been absorbing the nutes.

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I would flush. Acidic runoff is usually from overfeeding and/or feeding without enough runoff.

Next time, add 1-2 Tbsp/gal dolomite (fine textured, like Fertilome Hi-Yield Agri. limestone). This won't fix overfeeding. You'll still want to monitor runoff ph and ppm as an indicator of salt buildup. But, it helps. Feeding with 20% (or more) runoff helps avoid it too.

For now, you could cultivate fine-textured dolomite into the top soil. About 1 tsp per gallon of medium, and water it in (when it needs water/feed next time). Do that 2-3 times. But, dolomite takes 10-14 days to start working. If you have nute lockout due to acidic soil, you could foliar feed during that time.

Be sure to let your soil dry before watering. The soil ph rises as it dries. If you keep it wet it will be like low ph.

az2000 said:

I would flush. Acidic runoff is usually from overfeeding and/or feeding without enough runoff.

Next time, add 1-2 Tbsp/gal dolomite (fine textured, like Fertilome Hi-Yield Agri. limestone). This won't fix overfeeding. You'll still want to monitor runoff ph and ppm as an indicator of salt buildup. But, it helps. Feeding with 20% (or more) runoff helps avoid it too.

For now, you could cultivate fine-textured dolomite into the top soil. About 1 tsp per gallon of medium, and water it in (when it needs water/feed next time). Do that 2-3 times. But, dolomite takes 10-14 days to start working. If you have nute lockout due to acidic soil, you could foliar feed during that time.

Be sure to let your soil dry before watering. The soil ph rises as it dries. If you keep it wet it will be like low ph.

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Awesome info, thanks. Is Dolomite usually in places like Wal-Mart or Home Depot? Where would one usually find thisÉ

Coppertop87 said:

Awesome info, thanks. Is Dolomite usually in places like Wal-Mart or Home Depot? Where would one usually find thisÉ

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Probably not Walmart. A local gardening store? Ace Hardware? Be sure it's dolomite, not hydrated lime. It's often called agricultural lime. It should have about 2:1 Ca:Mg. (If it has a tiny amount of Mg, contains Ca Hydroxide, it's hydrated lime and isn't good except for very specialized uses in very small amounts.).

From what I've read: it should be fine textured like sand or flour. Pellets take too long. If you can only find pellets, then mash them into bits.

You can use hydrated lime to raise soil ph. I used it 6 times over a couple months as I fought acidic soil (before realizing it was overfeeding and salt build up). I would mix 1/2 tsp/gal water, the water ph would be about 10-11. I'd pour it into the soil, let it set, then feed -- which was like a flush. I'm not suggesting you do this. Hydrated lime isn't good for your plants. I'm just saying that hydrated lime has a use in extreme cases where you think you'll lose the plant. I wouldn't have any trouble doing it again. But, you'll want to figure out why your soil turned acidic. My guess is overfeeding. But, it could be due to not enough dolomite in the soil. I grow with Pro-Mix HP but have never grown without adding dolomite. I never get acidic soil, but I did when I overfed. If I'm careful to get a lot of runoff (mini flush each feed) and keep the nutrient strength lower than what I used to do, everything turns out fine.

Peat has a Ph of around 4.9. I rarely have to run my CNS-17 upwards of 800 ppm. Yes I believe botanicare schedule is around 1800 ppm at max dosage.

Coppertop87 said:

Hey guys,

I'm kinda confused now. I checked the PH of my runoff and it was at 4.0, then I flushed them with about 4x or more of the volume of water that the pot can hold with Reverse Osmosis water that was PH'd to 6.5. Checked runoff and it was still at 4.0

Then I poured in some water with a higher PH at like 9.0 and the runoff was still 4.0

What am I missing here? Is my runoff supposed to be in the 6-7 range? I am soiless. If so, how the hell do I get my runoff to test in that range?

Click to expand...

don't do runoff. ph water only after you've added your nutes. soiless grow should be at 5.8 with 5.9 being "acceptable"..maximum nute uptake will occur at 5.8.

http://www.amazon.com/Bluelab-PENGTB-Growers-Toolbox/dp/B00H90O26C/ref=sr_1_6?ie=UTF8&qid=1424972279&sr=8-6&keywords=ppm ph meter

boilingoil said:

Peat has a Ph of around 4.9. I rarely have to run my CNS-17 upwards of 800 ppm. Yes I believe botanicare schedule is around 1800 ppm at max dosage.

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you should be no higher than 800 - 1200 PPM's on any grow full bloom..your manufacturer wants you to buy their product. and you are falling into their trap.

check my sig #4, 2 inexpensive bottles, has the calcium, maganese, manganese, sulphur..just picked up a quart of "b" yesterday at hydro $14. it's $17 online.

why do you guys like spending money on water? i'll never know.

reapersfamiliar said:

you should be no higher than 800 - 1200 PPM's on any grow full bloom..your manufacturer wants you to buy their product. and you are falling into their trap.

check my sig #4, 2 inexpensive bottles, has the calcium, maganese, manganese, sulphur..just picked up a quart of "b" yesterday at hydro $14. it's $17 online.

why do you guys like spending money on water? i'll never know.

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Don't be ignorant, all plants require nutrients differently. I have some that feed 1500ppm at week 6 of flower. Don't fall into this guys "know-it-all" trap, Learn your plants, and your growing skills will increase.

reapersfamiliar said:

don't do runoff.

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WTF are you talking about guy, how dense are you? I know that you know how to use google, quit perpetuating misinformation. This guy is asking for help with what he has, he doesn't want to copy you or emulate you.

@Coppertop87 Please don't listen to this guy! He's gonna -f- up your progress. Keep checking the run off ph, remember though, its just 1 indication of whats going on. Don't worry so much about trying to make the run off 6.0+ ph, if your plant is happy then it (checking run off PH) is not required. Continue to water to waste at, at least 20% of the containers volume. Keep in mind to that promix acts as a "buffer" the same way soil does, meaning that what you do Monday probably won't show til Sunday, don't go over board with the PH monitoring...