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Another pH question

gr0w

Active Member
hey guys.
having a Ph issue and did't really find my answer after doing about an hour of research. so here I am starting yet another thread on Ph issues :( sorry

yesterday I did my res change and fill
I am using R/O water in a 20 gal Underwater RDWC. Using General Hydroponics FloraSeries 3 part and also CalMg+


last night everything was running perfectly, I was at Ph 5.9 and 1250 PPM for week 3 of my grow and was happy and went to bed.
woke up this morning to check on my girls and the PH was up at 7.0.


I then added 5ml of PH- to the reservoir and waited about an hour for everything to cycle through and went back and checked the PPM and PH. PPM is within the range for the week im in, water temp is 75* but the PH jumped all the way up to 8.03 as shown in picture.


it is sitting like this right now and don't understand what happened
can anyone help me out?

here is my res setup
i have air stone in each 5 gal bucket and 3 airstones in the reservoir.
 

gr0w

Active Member
thanks for that chart, will definitely print it off
but right now i don't know if the plants are drinking/ water level is going down
the res change is only 1 day old and just trying to figure out why my PH balance went crazy.
 

Scientific

New Member
but right now i don't know if the plants are drinking/ water level is going down
the res change is only 1 day old and just trying to figure out why my PH balance went crazy.
I'm puzzled as to why you don't know if the water level is dropping. A simple dipstick measurement should tell you that, and it's a really important daily measurement to make and record, especially as your plant grows and starts drinking heavily.

The chart is interesting, but like any troubleshooting tool, it has to be used as a guide and not a bible. Take careful measurements and notes and course-correct as needed.

That's the extent of my advice. My own pH levels mysteriously rose and fell throughout my grow and I was at a loss to understand what the dynamics were (and I have worked as a biologist and have built pH measuring equipment--I thought I knew about this stuff, but my reservoir's behavior knocked me off my high horse).

The one other thing I can tell you from experience, though, is that if you keep measuring / recording / correcting, eventually harvest day will arrive and you will be rewarded!

Before my next hydro grow, I am going to do a lot more reading on pH to see if I can't get a better understanding.

Two workarounds: Advanced Nutrients "pH Perfect" system has a loyal following of people who say it works well. And you could set up an automated pH monitoring system that automatically corrects. (I suspect that a really big reservoir would remain more stable as well. My tank was small and my temperature too high most of the time, and I suspect both were part of my problem.)

Just my .02. I feel your pain! Good luck, keep fighting the good fight, and harvest day WILL arrive! :)
 

gr0w

Active Member
Thanks for the reply!
The reason I don't know if the water level has changed is cause I adjusted the return flow pressure so there is more water in the reservoir right now than yesterday.
I messed up somewhere, just don't know where. This is my first rdwc grow.
 

gr0w

Active Member
LOL. All part of the journey. ;) You can read all you want, but it's not until you jump in that you really start learning.
yessir

what do you guys use when you start getting a sludge/ build up in your res? notice the buildup in my res pic?
 

Scientific

New Member
yessir

what do you guys use when you start getting a sludge/ build up in your res? notice the buildup in my res pic?
I didn't have any sludge at all after a 70+ day grow in a small reservoir. I had lots of circulation (air stone + two small pumps) and changed my nutes every week (GH FloraSeries and CALiMagic CaMg supplement and Hydroguard), but that's it. I didn't even completely drain the tank but just pumped out what I could.
 

gr0w

Active Member
oh yeah! crap
i just grabbed the GH flora series and CaMg+ and meant to grab a liter of the hydroguard and completely forgot.
guess now I have something to do tomorrow :p
 

Weezze

Well-Known Member
yessir

what do you guys use when you start getting a sludge/ build up in your res? notice the buildup in my res pic?
Not sure about the "sludge/ build up", but I change the bucket every week, with a 24h of flush with just water.
 

Weezze

Well-Known Member
Do you mean nothing but water when a plant is present? If so, I would be worried about both pH and osmotic shock to the plant.
Yep just water, but I lower the ph.
Last week, the ph was 5.7 and the ppm 180 for 24h.

She seems ok with that! :)

 

Scientific

New Member
Yep just water, but I lower the ph.
Last week, the ph was 5.7 and the ppm 180 for 24h.

She seems ok with that! :)
So... I can't resist asking, even though the plant tolerates it, what benefit do you think there is in cutting off it's food supply for a day?
 

Weezze

Well-Known Member
So... I can't resist asking, even though the plant tolerates it, what benefit do you think there is in cutting off it's food supply for a day?
I always done this, I though that was the norm! lol! It's to "clean" her from the nutrients.
I guess I have to rethink that! :30:
 

gr0w

Active Member
I always done this, I though that was the norm! lol! It's to "clean" her from the nutrients.
I guess I have to rethink that! :30:
The last two times i just drain the res, run a bit of water for the left over stuff on the bottom and then suck the rest out with a shop vac then refill with new nutrients. (And then mess something up ahaha, hence the post :p)
 

Lazarus13

Well-Known Member
I always done this, I though that was the norm! lol! It's to "clean" her from the nutrients.
I guess I have to rethink that! :30:
I clean my rootmass between veg and flower to get rid of some of the salt build up but just with a dunk and swish in ph'd ro and then re-inocculate with whatever bacteria/fungal product i happen to be using... Usually Great White. Just how i do things but i noticed beforebi started doing it, my ph would swing and drop like crazy in flower. The grows ive done since doing it this way the ph has stayed nice and steady.
My $.02
 

gr0w

Active Member
follow up question for anyone looking

I am currently able to use R/O water but was wondering about using both my tap water and R/O to possibly help keep PPM and PH closer to my goal range?

My PPM from the tap seems to be 365 and ph of 8 (my area says it has soft water, but idk the range in which that means)
is there a formula or anything to determine how many of each I can add into my 25Gal system?
or should I just keep using the R/O

also, another question.
I am using GH Micro, grow and bloom. I also have/use GH CaMg+, RapidStart root, hydroguard and FloraKleen
do you guys have any suggestions as to how I should use these? which order to add them? what not to use? when to use ect
my system will be approx 20-25 Gallons (still working out kinks after adding a new Reservoir)


had to take them out of the pots while I run some FloraKleen in the system for the night
 
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