Black widow ph keeps dropping

Growing black widow just switched to flower 2nd week. My ph keeps dropping from 5.8 to 4.5-4.9 over night. I found my filter got clogged burnt up fan must had been dustier n my shop than i thought. 5x5 Grow tent. Im growing using distilled water my tap has over 420 ppms. I have been using all GH nutes. I changed out water ran GH Flora clean through it was fine for a day now its back again. My plants were so beautiful now im loosing them. Its been going on for over a week. I keep using GH ph up to try and keep it back up. Please help…

Have you calibrated your meter recently? When i dont believe my meter reading i immediately calibrate. And calibrate about twice a week. I use mine 10+ times a week.

Pictures help.
What medium are you growing in?
Sounds like a root rot problem to me, but there are many reasons this happens besides that.
If its DWC/hydro then keep changing water and add a little h2o2 to help combat the possible root rot...how do the roots look, feel and smell?

Thanks for asking for pics. I didnt want to lash out at the ignorant grower. Were not psychic. Greater than 50/50 odds its a fucking purple and mauve pic taken under LEDs?

Mak'er Grow said:

Pictures help.
What medium are you growing in?
Sounds like a root rot problem to me, but there are many reasons this happens besides that.
If its DWC/hydro then keep changing water and add a little h2o2 to help combat the possible root rot...how do the roots look, feel and smell?

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I will take pics and post them. I e ran flora kleen through it twice when changing water.

SubB1 said:

I will take pics and post them. I e ran flora kleen through it twice when changing water.

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So what are you growing in...DWC/Hydro ?
And yes as mentioned above...take pics in natural light please...grow lights can hide the true colors that someone can/may be able to help diagnose easier.
I have not used flora kleen myself, but if it is root rot then it may get expensive running that daily until pH stabilizes again.
I think changing water daily is your best bet at this point...until you get a stable pH anyways.
And when changing the water be sure to clean the system fully (buckets, res, pipes and pumps etc) due to any bad residue(s) left can/will just allow the trouble to come back again. Disassemble and clean the best you can and try to keep the plants (roots) wet as you can while they wait for you to finish.

Heres the pics from today! I took alot of bad leaves yesterday! Im growing in a rdwc with water in 5 bucket system with one as a reservoir.

Here is pic of my roots

SubB1 said:

Here is pic of my roots

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LOL...I think you may have just made @Snoopy808 's day with the blurple pics.
Well the roots seem to look ok...do you notice an odor in the bucket? Do they feel slimy? Do they break easily ?
If the above is no then I'd say you may have a pH pen problem...change the batteries and do a calibration on it.
Then test it a few times and see how its reacting to the same fluids...use 3 or 4 cups with water + pH up and another set with pH down (6-8 total) at different pH's and every 15 mins or so see if the pen is still reading them the same. They may drift slightly by a 0.1 or 0.2, but not much more within a few hours at minimum.
Then move on to adding nutes 1 at a time from there...something being used has to be causing the drift like that if not the pen itself.
Will check back in a little while...scrogging some Smile plants atm...lol

Anyone working on a blurple filter plant nutrient deficiency chart for noobs?

Personally if you’re using distilled water then you are almost devoid of any chemicals to help stabilise the nute mix.


Personally if it were me I would start by adding Ca and mg to your source water to up your PPM to around the 150-250ppm depending upon scale .5 scale 150ppm .7 scale 250ppm.

This should help to stablilise your nutrient mix after you add your nutes.

The Ca and mg act as a slight buffer for your ph.

SubB1 said:

Growing black widow just switched to flower 2nd week. My ph keeps dropping from 5.8 to 4.5-4.9 over night. I found my filter got clogged burnt up fan must had been dustier n my shop than i thought. 5x5 Grow tent. Im growing using distilled water my tap has over 420 ppms. I have been using all GH nutes. I changed out water ran GH Flora clean through it was fine for a day now its back again. My plants were so beautiful now im loosing them. Its been going on for over a week. I keep using GH ph up to try and keep it back up. Please help…

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Get some ph drops to check the ph. When ever you have a ph drop like that its best to check with the drops to see if the ph meter is out or not before you go adding ph up or down to correct an issue that isnt there. Im talking a big fluctuation not just a little swing.

I wouldnt use the flora kleen stuff I dont think its needed.

add in some calmag first to bring the ppms up a little since your using distilled water and or add a little tap back into the res. to help stabilize the water.

Always make small adjustments to the ph when adjusting it. You dont want to add to much up and then have to add down right after it.

Thanks everyone.

Bernie420 said:

Always make small adjustments to the ph when adjusting it. You dont want to add to much up and then have to add down right after it.

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This is good advice.

I personally dilute my pH up and Ph down into water and have it in an easy to use squeeze bottle.

10ml ph up or down into 100ml Of water.


Any undiluted ph up or down can cause a drastic shift in ph when it hits the nute mix.

Any mix subjected to ph4 or ph8 respectively can get precipitation of nutrient ions out of the nute mix.