Low PH - Flush?

Help! I am on the last day of week 5 Flower. Fed and PH Rain water at 6. Ph came out as 5! Do I need to flush? If so, I am in 7 gal pots. If I have the rainwater is that best? It’s about lights out - is it bad to wait until morning? What do I do to feed them after, or do I wait until they dry out?
I also saw someone mentioned Lime. Can I topdress and water in and skip flush? Ugggghhh. I’m so close……

-What strain, Photo ILGM Purple Haze
-Age of plant 18 wks
-Method: HFOF
-Vessels: Plastic 7Gal
-PH 6 Solution, runoff 5
-PPM/TDS In 1280 out 1250
-Method used to measure PH Drops and TDS Pen
-Light system Mars Hydro F4800
-Actual wattage draw of lights
-Current Light Schedule 12/12
-Temps; Day, Night
-Humidity; Day, Night
-Ventilation system; AC Infinity
-AC, Humidifier, De-humidifier,
-Co2; Yes, No


6.5 is sweet spot for ph.
Do u use photone meter for your light?
The app is free and works to set right dli…
As long as u ph water going in.
What are your runoff numbers?
These numbers let us know if the girls are hungry.
What nutes?
When did u flip to 12/12.?


After putting Fox Farm trio in my rainwater I’ve been consistently watering about 6PH. I’d like to raise it to 6.5 but every time I try use UP, I end up making it way too alkaline (even if I only use .25 per gal). Also put in 1tsp of CalMag.

PPM of Channel was 1426 IN and 1250 OUT
PH changed to 5 when I checked runnoff.

I have not checked DLI, but I will.

So do I not need to worry about the runnoff being so acidic?

Im using ph up. Ive learned to draw it up in a dropper and drop one drop at a time in a gallon container until ph is reached. My runoff was 6.3 last watering, so i ph’d up to 7.0 to try to get my PH around 6.5 to 6.7 for nutrient uptake in soil.


Dont pH when you use rain water it takes on the pH of the soil

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I’ve been PHing after adding nutrients. Is that reading correct? It seems to be a consistent 6. My concern is that my runnoff is now reading PH of 5.

Today PPM of runnoff in trays are 1500 and 1100 Do I need to flush? If so, should I flush with same rainwater OR use tap water ph’d?

If I use tap water ph’d to 7 don’t I need to wait a day for chlorine or something to come out? I may even have drops for that from fishtank stuff I can use. Maybe I don’t need to do anything….just looking for confirmation!

Today is 1st day of week 6 in flower. Thanks!
@ChittyChittyBangin @beachglass
@OGIncognito @PurpNGold74

You can use the fishtank stuff, thats what i use. It got me in trouble though so thats why im having to ph up. Im going to stop using it and use the evap method for now on though. Might use it in a quick pinch. Id ph up to 7 on your next watering. I learned during flower ( if using living soil ) you want your ph to be a little higher than 6.5 to allow more of certain nutrients to be able to be taken by the roots. Im now fighting deficiencies because of the ph issue, but have since corrected and its a wait and watch game.


Use tap water ph to get back in range then continue your rainwater just don’t ph the rainwater because you really can’t. Rainwater is neutral and takes on the soil ph :+1:

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I usually water 1 gal and get runnoff so I watered both of them with 2 gallons with PH 6.5ish tap. Runnoff PH was still 5. Then I did a slurry test with a Burpee PH meter and its falling in the 7 range. I’m not sure what to believe. I think the plants look ok, so I’m thinking to err on the wait and see side?

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Don’t worry about runoff if the plant is healthy just what goes in.

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