What Causes Ph to Drop?

polishfalcon420

polishfalcon420

Well-Known Member
this particular strain is trainwreck and the large one can deffinately handle 1450ppm. I have no signs of burn at all. I have had this same issue with various strains and Ive had low ppms and high ppms. the last northern lights cross of mine that I grew yielded over a pound and was at 1800ppm during peak flower and this plant looks like it will atleast put out close to an lb. this strain is deffinatley hungry the ppms have always dropped with water consumption it was finally 1450ppm or so that it stayed most consistant and it still drops about 50ppm. I agree it may be to much nitrogen but the rest of the mix is getting used up consistantly.
 
polishfalcon420

polishfalcon420

Well-Known Member
mr.smileyface said:
Im just saying what i would be doing for my strain. He mententioned kush.. So around a 1000 is good.
Click to expand...
this round is trainwreck, and mt og kush #18 gets max out at 1200ppm just chopped one down that was more of the stretchy pheno and hit 12 zips dried. I try not to set a standard for nute ppm and try to give the plant what it wants. I learned about overnuting almost 3yrs ago and since I have rarely burnt a plant once in a while I do get a little bit of curl over. one thing I do know is the greenhouse bubbakush was the most tempermental nute sensitive strains I have ever grown. the max I hit them with at peak flower was less than 1000ppm and they didnt burn but they curled up really bad. but yeah usually I dont exceed 1150 or 1200 but this plant is pretty massive like I said earlier its 5ft 4in tall and atleast 12ft around its bigger but my 12ft tape wont reach around it.
 
polishfalcon420

polishfalcon420

Well-Known Member
I dont think I explained myself quite right. the guy at the store meant if you have used ph down in a solution than you should not use the ph up later in the same solution in the cycle. like if you use down on moday and tuesday then your ph dives you shouldnt use the up. I also dont really mean to bash an I will give them another shot cause I do believe that most of the issues I have were caused by not using any calmag to start and thus the plants didnt get a very good start but now they look pretty good except for the already affected leaves. which I had a feeling that I was going to need it but the an dude said oh no our stuff is specially formulated and the only reason we make sensi mag is for the people that need to supplement their inferior nutes. it even says that on their site but once I had the issue I started looking on the net more on the percentages in their stuff and people using AN with ro and found a study that broke down a bunch of grow nutes and AN was the only company that did not pass because they did not contain the amount advertised on the container and guess what, the two were cal and mag.
 
polishfalcon420

polishfalcon420

Well-Known Member
I just wanted to say thanks to everyone that replied. I started this thread not cause I had an issue with the plants but cause I wanted to know what was actually taking place when this happens. now I believe I have a better understanding of the issue and it will deffinately help me in the future. now one more look at it. I may be looking to far into this but when this happens the amount of nitrogen is basically to high or rising causing the ph to drop. now is it actually because the nitrogen is rising or could it be that the nitrogen level is the same but its not being balanced because the loss of phosphorous. meaning that if the plants are draining the p out and not the n it throws the natural balance off? so basically what Im getting at is when this happens could you just use a pk booster to replace the p thats missing and use less base nutes containing the n? thanks again everyone its nice being able to pick other brains that actually have a better clue about what going on than myself.
 
303

303

Well-Known Member
masp84 said:
Sorry I wasn't clear enough. And yes they have defenses for even that! what I meant was that If the nute component absorbed are more akaline than acidic the solution PH will go down and vice versa, as the nutrient salts gets more concentrated within the solution in unbalanced ratios.

PH rises because most elements require a slightly lower PH than 6 to be available. There are only 2 elements that need a higher pH which are Mg and P. Both are required enormously by MJ plants but not nearly as much as N and K which both lower the PH. So your plants should eat the N and K, rising PH slightly as the more alkaline elements will still be present in the solution so the opposite is true. In hydro when I see constant PH lowering is usually because bad bacterial growth or Salt build up in the root zones.
Click to expand...
I'm having the same problem, although my ppm's are around 680-720. Ph starts at 5.8, wake up in the morning and its at 4.1. ppms drop very very slightly. But this is reoccurring everyday and I can't figure it out. Maybe as said in the above quote salt build up? My water is super hard (210ppm). I have been using h202 thinking bacteria maybe the culprit, but hasn't changed anything. I'm also running 1500 ppms co2, I've read somewhere it can drop into your res's and drop the ph? Any thoughts? I'm week 4 flower, recirculating hydro.
 
303

303

Well-Known Member
303 said:
I'm having the same problem, although my ppm's are around 680-720. Ph starts at 5.8, wake up in the morning and its at 4.1. ppms drop very very slightly. But this is reoccurring everyday and I can't figure it out. Maybe as said in the above quote salt build up? My water is super hard (210ppm). I have been using h202 thinking bacteria maybe the culprit, but hasn't changed anything. I'm also running 1500 ppms co2, I've read somewhere it can drop into your res's and drop the ph? Any thoughts? I'm week 4 flower, recirculating hydro.
Click to expand...
What I'm explaining smell like nute lock out??
 
doniawon

doniawon

Well-Known Member
PPM goes up, Ph goes down=plants require less nutes.
PPM goes down, Ph goes up=Plants require more nutes
PPM stable, Ph goes up=Equilibrium=Good thing. general rule for hydro
 
303

303

Well-Known Member
doniawon said:
PPM goes up, Ph goes down=plants require less nutes.
PPM goes down, Ph goes up=Plants require more nutes
PPM stable, Ph goes up=Equilibrium=Good thing. general rule for hydro
Click to expand...
The strain Im using ive done so many times before at 1000ppms almost all the way thru, this time something is going on, ph dropping, ppms going up, at only 700ppms. I'm going to use florakleen for 2 hours then refresh with very light nutes and go from there. :wall:
 
303

303

Well-Known Member
doniawon said:
you using hygrozyme or peroxide?? i forgot whats in the mix already..
Click to expand...
Florakleen, is just a salt/niutrient clearing solution, it doesn't contrain h202 or hygrozyme. I tried h202 the last week, didn't help. The bottle says to run the florakleen for 2 hours then replace with nutirents, which is what I'm currently doing right now.. Its dark though, hope that doesn't matter. I would think its better.. Although working with a headlamp sucks.
 
doniawon

doniawon

Well-Known Member
its probably root rot then.. you need to sanitize your root zone.. what strenght h2o2 did you use and at what rate?.. and its not gonna clear up over night.
 
303

303

Well-Known Member
doniawon said:
its probably root rot then.. you need to sanitize your root zone.. what strenght h2o2 did you use and at what rate?.. and its not gonna clear up over night.
Click to expand...
4TSP for 10Gallons, 35% H202, I dont believe I have root rot, they are white, really white.
 
doniawon

doniawon

Well-Known Member
hmm only other thing i can think of is your resivoire maybe too small for the number or size of plants. sometime a bigger res is required to keep things stable.. stumped?
 
303

303

Well-Known Member
doniawon said:
hmm only other thing i can think of is your resivoire maybe too small for the number or size of plants. sometime a bigger res is required to keep things stable.. stumped?
Click to expand...
No actually you were right, beginings of root rot, I ran florakleen, it removed a lot of the brown, they look a lot better now. I changed the res's, running 700ppms @5.8ph. Added 5TSP per 10 gallons. I'll keep adding a TSP or 2 every other day till res's run dry or i change them. I also went to the hydro store, the owner sold me some hygrozyme, but after reading reviews its not so much for riding bacteria, I think I'll return it, $40 POS.
 
mr. green thumb 01

mr. green thumb 01

New Member
I came across this post because my ph is rising over one full point overnight also. I think possibly my ph may be rising also due to adding the a beneficial tea brew and them dieing off. But overnight in a highly oxygenated tub id think they would multiply. So im just going to flush them and run plain water over night and see if it drops or rises. Been cruising along using dynagro with a few choice additives and like hmm ill give a.n a shot and them bam problems left and right...Also I got a bottle of part B that had chunks in the bottom. Not so good imo for a $70 liter set. Started with wonderful an connoisseur and no calmag as recommended and guess what 3 wks in my plants were screaming for cal and you cant just get them to take cal overnight immobile element takes time to absorb through the root zone. So in peak flower and thank you a.n for depriving my babys of their cal now my yield will suffer. Then I tried to hit them with a good bit of calmg but its too late the damage has been done and is permanent..

Also the conni was the ph perfect but the ph issues started more so once I went changes the tubs w/ technaflora because those bottles had no chunks. Also their npk ration are closer to a.n then that of d.g. I had not encountered any problems before with b.c nutes. I get better yields with my custom d.g mix but have been wanting to dabble with different npk ratios to see what happens.
 
O

OsamaBeenTokin'

New Member
I am so happy I googled this. I thought I was the only one with this problem. I got the same situation, for me it's week four of my flowering... It's the week where there is the most nutes added... 720 ml ab magnesium sulfate... 0-52-34..ect...so I believe the over fertilization might be the cause...I also noticed it worked OK with the Jean guy but when I switched to growing purple Kush the pH drop would show on the 4th week...so fertilizer recipes aren't one size fits all...anybody know a good one for Pk let me know.
 
blackforest

blackforest

Well-Known Member
polishfalcon420 said:
I agree but I just cant see where I am using that much nitrogen in the first place myself. last mix was 10ml floranova bloom and 7ml koolbloom per gallon. the nova is a 4 8 7 npk value and the koolbloom is 0 10 10 that put me at about 1450ppm. it does look like the larger plant may have a very small calmag def if at all but it does have red petioles and fan leave stems starting on the larger main branches. Im not to sure if that goes with the strain or not. I upped the koolbloom last res change due to this and have not really noticed much of a difference and its budding like crazy. there both actually very healthy plants but Ive just been trying to figure out more on the ph dropping cause Ive had it happen in all of my successful grows so far and in a couple that didnt go so well. successful meaning 2 lsd plants under 1000w net 27oz dried 2 northern light pure gold crosses of mine 29oz dries bud there was a couple others like a lemon skunk and a querkle together under a 1000w lemon skunk hit 15oz and the querkle hit 10oz. but on the other hand Ive had 2 bubba kush under oe light and only hit 12oz total between the two but they were kinda messed up from the start and could never figure them out. so most of the time I achieve pretty good results. this ph thing is just kinda getting to me maybe it is just the norm in my setup as is why my buddies is doing the same thing. I just keep reading all over that a healthy hydro setup the ph should rise.
Click to expand...
Same thing happens to me in all my hydro cycles. I'm in week 5ish and yep, the PH drops. Before this point, it would always rise. It kept happening regardless of what I did to my system, so now I just expect it. When it gets to this point, I basically keep my top off rez at 7+ ph and more or less it helps keep the ph in the system constant. At this point, I will also bring my ec down to about 1.0, they seem to like it better at this stage in flowering.
 
Gregor Eisenhorn

Gregor Eisenhorn

Well-Known Member
blackforest said:
Same thing happens to me in all my hydro cycles. I'm in week 5ish and yep, the PH drops. Before this point, it would always rise. It kept happening regardless of what I did to my system, so now I just expect it. When it gets to this point, I basically keep my top off rez at 7+ ph and more or less it helps keep the ph in the system constant. At this point, I will also bring my ec down to about 1.0, they seem to like it better at this stage in flowering.
Click to expand...
I've just experienced the same thing just today, I've just hit the 5 week mark.. I checked the pH and it as 5.3 and I haven't touched the reservoir in days.
I thought it was root rot at the beggining, because RR is known to cause pH drops, but this thread chilled me out. :D I'll just monitor the pH and add some pH up if need be.
 
You must log in or register to reply here.
Top