High soil ph what should i do

Strain; Type, , or 3 plants trainwreck sativa all from feminized seeds Soil in pots, Hydroponic, or Coco? System type? soil in pots Happy Frog soil
PH of runoff or solution in reservoir?
What is strength of nutrient mix? EC, or TDS
Indoor or Outdoor Light system, size? indoor 600 watt led
Temps; Day, Night 70-70
Humidity; Day, Night 40%-45%
Ventilation system; Yes, No, Size Yes 8" dk hp should be big enough
AC, Humidifier, De-humidifier, yes
Co2; , homegrown exhale co2 bag

my plants are 4 weeks old. I have only fed with 6.5 ph water since they were seeds. first two to three weeks plants looked good.in past week or so noticed leaves hooking and brown and yellowing spots on lower leaves I tested soil ph and was above 7. I flushed with 6.5 until ph was good .I did not notice any difference before next watering{ 2 days} tested soil again back above 7…just gave first dose of nutes (1/2 strength} last watering with a ph of 5.5 to bring down soil ph. which it did to between 6.3 and 6.6. this is only happening to 2 plants other plant looks good ph slightly high.is this normal. should I be bringing down ph of water every feeding to lower ph of soil?any help greatly appreciated thx

How old are your plants and what are you feeding them?

Duh, see it now sorry. It is early for nutrients so I would not continue that as of yet. What is your method for determining the soil ph?

Can you provide a picture in natural light?


Sounds like a soil probe meter issue @Myfriendis410 @rasta1


That’s exactly what I was thinking Bob.

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I have blue lab soil teste rwas one reccommend by local shop paid $200 for it and calibrate it regularly i also check runoff. 3rd plant pic is healthy one first and second plant pics leaves curling can see small brown spots on second pic I have already cut off very bottom leaves because they were dead

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Have you done a runoff ph to see if the two match up? Because that’s pretty far off to be looking good.

yes I have in past. just watered one plant with 6.5 both water and soil meter read same in water and tested with 7.0 reference solution.the run off ph was 7.0 soil ph 6.8. I am using earth juice ph adjusting crystals. should I water the next few times with a lower ph water or should I flush again? so this is not normal for soil ph to rise between feedings?


The water pH in is 6.5 and the runoff is 7.0?

Are you using nutrients?

Looks like he posted a support form at the top. I would guess it’s too early for nutes and a few flushes with pH 6.5 water might be needed to stabilise the soil pH at 6.5

Says he’s giving nutes in post one. Also says happy frog which I use and soil is always spot on 6.5

@DieHigh55 @rasta1

I think you are adjusting too far. Watering at 5.5 in soil is 10 points low. At the lowest you should have tried maybe 6.3 or 6.2 but not any lower than that.

Let’s get a clarification on the nutrients and such. @rasta1

I use earth juice for nutes just used the nutes(I know its still a little early) once to try and bring down ph in soil.is there any condition or scenario that would explain why it keeps rising.as I said before have always phed water just before feeding at 6.3-6.5. I’m baffled and frustrated plants are getting worse by the day

Did you pH the water to 5.5 and then add the nutrients?

I don’t think giving nutrients at 4 weeks is wrong to do. Nor do I think that the nutrients are your problem.

I added nutes then raised ph to 5.5. I don’t think nutes are problem either since I was having problem before I introduced nutes

Do you have calibration fluid for your meter? @rasta1

yes 7.0 reference liquid and both meters are calibrated

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Draw your water into containers and allow chlorine to evaporate for 48 hours.

First check and calibrate meter as needed.

Note the pH of your source water. If it is 7.2 from the tap then it will almost always be 7.2. if you check it next week and it says 4 you could have a meter issue.

If your adding nutes, add them to the water before adjusting the pH

pH your water to 6.2 using meter and pH up or down; going in.

Water to runoff and then check the pH of the last bit of runoff.

@rasta1 next time Make sure and clean up most of the runoff water and collect and test only the last runoff. Let us know please tag us like @bob31 so we see that you tagged us! If you still get a crazy high pH just keep giving her PH water and flush her down. I will tell you i use Happy Frog and i haven’t experienced any issues with pH. It could be that you got a clump of something that didn’t mix properly with the rest of the soil…

I fed with 6.4 water and still had a reading of over 7 on run off. flushed with half gallon (plants in 4x4x4pots)and did not see any to little change in ph runoff. plants are ready for transplant so I flushed one knocked of any loose soil and transplanted in fresh soil hoping new soil will promote growth(plants have pretty much stopped growing and leaves dying from bottom up)and help reduce ph in soil around roots hopefully it will not raise ph in the new soil.whas that a good idea? should I just keep flushing? @bob31 @Myfriendis410

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I would stop flushing and water normally with ph 6.5 water and see how your girls do. Once they perk up you could start your nutes again.

Is it possible that this all started from overwatering?
That’s what I’m leaning towards… :wink:
You need to let them dry out really good before watering again… I think your soil is becoming anaerobic from being over-watered which is leading too crazy pH swing… :wink:

:v: :sunglasses:

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