Soil ph Reading 5.0? Can't be right.

Hello all,

I am currently on week 3 of my grow. I am using FFOF and have been using pH adjusted water to 7 until a week ago on my first feed, just big bloom. today I fed them 3/4 tbsp big bloom, 1 tsp grow big, 1 tsp bio root and 1/10th tsp open sesame (they're autos in preflower). I checked my ph before feeding and it was 6.4 so I let it be and didn't adjust. I waited for runoff and checked it with my pen and it read 5.0??? I rechecked with my liquid solution and it read the exact same thing.
The plants are looking great, nothing wrong with them at all. how can my ph be that low if there had never been anything in my bucket under 6.0? I don't think this is right because they are doing so good. Any thoughts or has anyone seen this before?

whitnasty1 said:

Hello all,

I am currently on week 3 of my grow. I am using FFOF and have been using pH adjusted water to 7 until a week ago on my first feed, just big bloom. today I fed them 3/4 tbsp big bloom, 1 tsp grow big, 1 tsp bio root and 1/10th tsp open sesame (they're autos in preflower). I checked my ph before feeding and it was 6.4 so I let it be and didn't adjust. I waited for runoff and checked it with my pen and it read 5.0??? I rechecked with my liquid solution and it read the exact same thing.
The plants are looking great, nothing wrong with them at all. how can my ph be that low if there had never been anything in my bucket under 6.0? I don't think this is right because they are doing so good. Any thoughts or has anyone seen this before?

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Did you add any Dolomite lime when you planted? How about perlite?
Are you checking the soil wet or dry?
Your soil PH will not show a change right away just because you water with a different PH.
Water PH usually drops after nutes are added to it.
http://www.wikihow.com/Test-Soil-pH

I did not add any dolomite lime, however I did add in some extra perilite.
I do have some dolomite lime at my house however.

I checked the runoff about one hour after feeding them today. Before adding nutes my pH was at 7.4pH and after mxing in all of my nutes my pH was right around 6.5pH.
Overall, all of the girls are looking very good, and I have not checked my pH runoff up until today, because I have been using just plain 7.0 water for the first 2 1/2 weeks or so.
I just do not see how it can be that low and the girls look so good. I have read alot of places that runoff is not an ideal indication of soil pH, and I have been reading around that FFOF seems to read low runoff quite often.
Anyways... Here are some pics from today, right before I added nutes...

And I am 100% sure that nothing below 6.0pH has ever entered those buckets, and I checked the runoff on two of the girls today and they were both at 5.0?

I am beginning to think soil runoff is not a great indicator of real soil pH, because they are all extremely healthy looking at the moment.

Any more ideas guys?
I am just freaking out over nothing and should I just leave them alone, because they look great right now?

I was so happy about this grow, everything had been going really well, they look healthy, and then I check this today, and its all fucked up now and theres a risk of losing everything I have done so far, not to mention the massive amount of money (start up costs mostly) to get all of this going. I am beyond livid at this point.

I have read though, that for soil growing, pH runoff is not an accurate measurement of the pH of your soil, so maybe that is why everything looks great, and I know that everything that has gone in, is correct, yet I am still getting these fucked readings.

whitnasty1 said:

Any more ideas guys?
I am just freaking out over nothing and should I just leave them alone, because they look great right now?

I was so happy about this grow, everything had been going really well, they look healthy, and then I check this today, and its all fucked up now and theres a risk of losing everything I have done so far, not to mention the massive amount of money (start up costs mostly) to get all of this going. I am beyond livid at this point.

I have read though, that for soil growing, pH runoff is not an accurate measurement of the pH of your soil, so maybe that is why everything looks great, and I know that everything that has gone in, is correct, yet I am still getting these fucked readings.

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glad to help ya...once i was in your shoe before...i tried to fix it and it got worse...you better leave soil ph alone ! if your plant looks good then dont worry about it unless you see any problem with defs...nute lockout etc. i dont bother to check PH in my soilless medium grow because i amended soil with garden lime. It kinda give me peace of mind. Next time , make sure to remember to amend your soil with lime alrighty ?

happy gardening

I definitely will next time!

I top dressed them all with dolomite lime today, and lightly watered them just to get the lime wet. I know it'll take a little while to kick in, but hopefully it will help out some. I had a ph issue two weeks ago, I thought it was just on one of them, and top dressed with dolomite and that one is starting to look much greener. took about two weeks for improvement to show. Hopefully these will work about the same.

you are definitely worried about nothing. your plants look fine. also... runoff ph is not a good indicator of soil ph. it only tells you what the ph of stuff that's washing out of your soul, not what's actually in it. the fact is that different salts vary in their solubility, and when you water/feed some will bind to soil particles or precipitate out of solution, and other ones will dissolve. the ones that dissolve and run out aren't in the pot anymore and are not a good indication of what is. runoff ppm is a different story esp if your using a soil less medium.

How often do you feed? Could be the beginning of nute buildup maybe. IDK I havnt messed with synthetics in a while.

That was only my second feeding and both were very light, ill post more pics from today.


The ppm of my soil Runoff was 950-1050, the strongest feeding on have given them thus far has been 400ppm. I really hope it's nothing, because they are looking great, the Skunks are starting to fill up with pistils and one of the NL's threw it's first pistil today.

I too have read soil Runoff is not an accurate method of figuring out the actual soil ph. I sure hope it isn't.

Either way, I top dressed with dolomite lime today and dissolved as much as I could in a gallon and watered over it, hopefully if there is a pH problem it will clear itself up in a week or two.

whitnasty1 said:

I definitely will next time!

I top dressed them all with dolomite lime today, and lightly watered them just to get the lime wet. I know it'll take a little while to kick in, but hopefully it will help out some. I had a ph issue two weeks ago, I thought it was just on one of them, and top dressed with dolomite and that one is starting to look much greener. took about two weeks for improvement to show. Hopefully these will work about the same.

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there you go ! you will be greenthumb in no time and hope to get your best meds as well.

what do u set your P.H at when u feed?