Newbie on first grow, High PH issue?

So this is my first grow and I’m using a mix of FF happy frog and FF ocean forest with 30% added perlite in a 5 gallon fabric pot. I never phed my water assuming the soil would buffer to the correct ph. Currently on day 40 from sprout and I’ve been noticing some brown spots on lower / mid fan leaves… I bought a ph pen to test my tap water and its super high, at 8.7 ph. I’ve only given one nutrient feeding at 1/4 dose using the FF trio on day 30. Temps are at 70-80FH and humidity between 55-70%

Just wanted to check if anyone has had this issue before. Will be testing run off later today. Cheers!



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Not a soil guy, but your Ph is high, soil has a happy around 6.5 to 6.8. The soil experts will help you get there.

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Do have PH down to lower your water source or nutrient solution? Do you have a TDS pen for checking the input and run off PPMs? Most nutrients after being mixed will drop the starting PH a point or so :love_you_gesture:

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I ordered some PH down but won’t have it for another week. Is it okay to use lime for the meantime? I do have a TDS pen and my tap water is at about 100ppm. I’ll be testing the runoff PPM later today. Cheers!

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Ph going in with that soil (in my experience) is very important to monitor. A good Ph meter is important.

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This generally raises PH, lemon juice is around a PH of 2.0-3.0 and can help, it does kill beneficial microbes though but those can always be added back :love_you_gesture:

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Thats a good number, too bad the PH is so high. Are you on a well? :love_you_gesture:

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Yeah, ground water from wells. Thanks for the info, I’ll update what my run off PH and PPM is later today.

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PH run off was at 6.7ph. PPM in on a half dose of Fox farms trio was at 250PPM… Run off was at 350 ppm. Does this look like it might be a Cal-mag deficiency since my tap water ppm is low?

Sounds to me like you need a feeding

Should I give a full dose on my next feeding? I know most use 1/4 or 1/2 dose of FF nutes but my ppm readings are so low…

Your ppms seem really low to me too. That’s why I say that but your plant is green. With fox farms you don’t wanna go straight to full dose. You have to build up to it. ( if you ever even reach a full dose) However you also use ocean Forrest and that stuff has a lot of nutes.

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Heres the chart i use when im using ff trio, never had any issues when following it other than i will add an extra tsp of what it says during flower because the plants tend to deplete it fairly fast sometimes

I also use ff happy frog and find that as long as the ph stays between 6.5 and 6.8 i typically only have to flush twice

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I’ve also been using that chart. I gave my first feeding on week 5 at 1/4 dose. On week 6 I started seeing those weird white / brown spots so I upped the dose and gave 1/2.

Do you feed every other watering? and at what stage do you flush? Cheers!

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Make sure your ph pen is calibrated properly. This part very important. Then recheck after calibration to make sure it holds. Hopefully you aint got the crappy yellow one on amazon.

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Feed water then feed again in a wet to dry cycle. Flush according to the chart.

@Jimmy229 sorry lifes kept me busy. I normally start with a full dose, then next time Ill water. If the ppms for the runoff from my next water are around or below 1000 then they get fed with the next watering. I always test the runoff ppms because it shows you how much nutrients are left in the soil from the last feeding.

As far as when i flush, its normally around the time they hit preflower then roughly 3 to 4 weeks after that but i typically just look for signs they need it. Drooping leaves 2 days after watering, spots on leaves, etc. Like @Poseidon1 said following the chart is always a safe baseline to follow as well.

Also if youre in week 6 and havent flushed yet, id say youre probably due for one if you havent already. Alot of the time leaf spots etc are the indications of lockout. Not always, but when in doubt my rule of thumb is to flush since it doesnt hurt anything