PH Always increasing in recirculating system?

[RobbieGanjaSeed]

Ok, so I've been growing dope for many years, and been doing it in hydro since 1997...but I'm still pretty much a "grow by numbers" kinda bloke when it comes to hydro. You know, mix this, flush that, bla bla...but the finer points are something that's eluded me, perhaps because I baulked at some of the text books I have looked into (some use words with more than seven letters in them!!), and maybe because my first love for growing anything is in organic, very bioactive soil. And somehwere deep in my physce, I believe I will return to my first love...oohh..ahhh...

 

Whatever the reason, I've been perplxed and subsequently asked many people, many times why the PH goes mad, always upwards in systems like flood and drain. I see many people raise this same issue in hydroponic forums and also seem left feeling unsure at the answers given, which unfortunately usually consist of such replies like "as plants use nutrients, the Ph alters...yeah right, well that's actually the question simply phrased a different way. I tend to want to know "why"a thing is happening ('m interested at all), rather than just knowing "it happens".

 

Suddenly I found the answer, the missing link is in my grasp, I have enlightenment!

 

I'm willing to bet who-ever is reading this already knows the answer and is wondering what took me so long, but for those who don't know, here it is (apparently. According to an artiocle I just read).

 

As plants take up Nitrogeon, they activelly manufacture bicarbonate, which of course releases it into the system if that system of course is always recycling. Even I have always known bi-carb is alkaline, hence raises the PH!

Simple!

 

But it also answers why some of us (mainly newer hydro growers) have this problem, worse than others, and in fact apparently (if everyone is telling the truth) some say it never happens to them at all.

 

I gather the more a plant tucks into the N, of course the more Bi_carb it will produce, and subsequently forever increase the PH.

 

Well excessive heat is one reason even dumb old me knows will make ya plant take up more N, and so moe experienced, better set up growers,who adequately ventilate and cool their rooms would suffer this problem much less, even to the point of perhaps not being noticable in the coler months at all? I've seen some people respnd to questions like "why is my Ph always rising?" with total perplexion, saying it's never happened to them. Well I gather it has to have, just maybe not so much it becomes a problem I can accept.

 

It's all making sense to me now. I just couldn't for the life of me uinderstand the frivolous way some people would dimiss the problem when a person raised the issue, and I guess it's becuase they haven't had the frustration of an overly hot room with plants using excessive N beofre! To those of us who have had rough grow set ups, perhaps often people who rent, and have set ups that arent that well arranged, the rasing PH in summer can happen so sevre , and so often it will drive u nuts.

 

In an almost seperate issue in this article, it was also noted that keeping the PH dpwn by use of acid alone will lead to a certain micro-nute being blocked out (I can't remember which one) and reduce flower size. Which is why I imagine people who again have inadaquately vented rooms, running hot, who have ever increasing PHs, using acid like it's water aren't happy with their yeilds!! I'm thinking the excessive acid is blocking essential flowering elements?

 

Ar...I am at peace.

 

rob

[Zaknefain]

depends what kind of acid you are using.

[ConvexConepiece]

Interesting as I have wondered this myself, but always just assumed that 'time' raised the ph and that it was reasonably inevitable...

 

I somehow wonder if the information you posted is the ONLY reason PH levels usually go up over time.... as I have just raised a few seedlings and even before they had hit the surface my ph was rising enough for me to have to keep it in check.... which sorta goes against it being the plants using the nitrogen. I use 'ph down' which im not sure what type of acid it contains due to the label being burnt off haha, but I assume its the 'best' sort of acid (im assuming its ammonium or something) to be using.

 

My nutrients also contain fulvic acid, which I have noticed REALLY helps in keeping the ph stable and means I can leave the res for a good week before having to check and adjust it, compared to a couple of days like I have had to before my plants were old enough to need nutes.

Edited March 8, 2008 by Gibbo

[RobbieGanjaSeed]

Great! You just had to come along and destroy my peace . I don't know why the Ph would rise if nothing's growing in it mate, but I asume the PH will rise (based on what I just read, and I am certainly no expert) by normal daily uptake of N by plants. It doesn't need to be excessive uptake, I just thought rough grows with bad ventialtion would increase the problem is all.

 

And Zac is dead right, I just re-read the aticle (wellt eh relative point) and it said the "sole use of nitric acid" will lock out phosphate.

So I am guessing there's a variety of acids we can use?

 

Like I said, I've been at this now for some years, but haven't ever taken it to heart. I might start doing so.

 

 

The article mentions nute mixes made for summer months as opposed to mixes for winter minths, and how mixes designed for summer time in the European tomaote growing industry was adopted here in Australia, only to find the mix wa 100% wrong for Australian summers. Apparently they lowered teh amount of potassium during summmer over there, while over here we actually need to increase the amountof potasium during sumer. Dont ask me why, but the guy writing this is some grewat professor gurur, and basd on experiences in the industry, not just theory.

 

i was thinking if one knew enough about nutrients and plant biology, then we might find using bottled nutes designed in Europe as an all year round nutrient here isn;t as good as if an expert were to make mixes to suit indviudal growing conditions as those conditions changed.

 

A grower I knew in Canada when I first came online 9clonr knows him very well) grew the mst awsome heads, and never used an additrve . He read miles of literature on plant biology and made his own mixes, and said the additves to increas bud size is a waste of money, that if you understand your plants needs, and adjust to suit those needs, you can grow a plant to it's fullest potential without using the popular additives that are arguably not so good for human consumption. i u saw the size of his heads, you'd have to agree.

 

I might be many years away from learning what he knows, but itmight be worth a look. Hell, i dont do much else these days, might as well bone up on this.

 

cheers

rob

 

ps, if nothing else,it might save me from unsrupulous hydropinic salesmen. I have askd a bloke in a hydro shop some years ago why my PH was riseing through the roof every day . He's probably the best hydro shop guy in many miles around here too. It was a very hot time of year, I had no ventialtion at all, and he never even mentioned this as a possability. What he said was "maybe you have a bad batch of nutrients with precipitation occuring. Here, buy some fresh new nutes and let me know how you go".

What a crock! But he sold a new batch of nutrients before he beganto explain the heat could be doing it.. gee money brings the worst out in people.

[ConvexConepiece]

Sorry to ruin your day of feeling like you've solved the mystery of your life haha.

 

The other 'assumption' I have is that the acid evaporates from the res solution a little quicker than the water in it...

 

But hey, if you feel like you have nothing better to do than find out exactly why this happens, feel free to inform the rest of us

 

edit: on the heat issue, although I have 'decent' ventilation, temps here in SA lately have been rather hot and so that may contribute to the problem, however when I was growing in winter last year I still recall having to adjust the ph regularly....

Edited March 8, 2008 by Gibbo

[RobbieGanjaSeed]

Yeah I think no matter how well cooled a room is, or how many or large the plants are in the size res. tank, the PH has to increase if it's going to be releasing Bi-Carb into the solution as an exchange for Nitrogeon.

I was just thinking of the crazy uncrontrolled leaps of Ph jumps that I personally have experienced, and have "heard" others worry about.

I think anyone that claims their PH doesn't rise at all either doesn't check their Ph, has no plants growing in their system, or is lieing.

 

I'd say daily checking and adjusting of the PH is always gonna have to be done to some extent. But bugga me, some of the times in my past it hasn't been able to be tamed at all, just right of the scale. In those times, I'm sure I had a heat problem=excessive N uptake=massive bi-carb indcution.

 

Bloody well encourages a run to waste mentality that's for sure .

 

cheers

rob

BTW, I don't know if this is the "sole" reason Ph will increase either. It's just an article I read regarding nutrient sufferages as diffferent levels of nutes were used or even exhausted in the tank.

these guys use meters to test for every nutrient individually of course, I'd hate to think what that woul dcost. They aren't just waving a EC meter around like we do and assume that the electolysis is reading "x", everything must be groovy.

[Reverend]

O.K. last night I filled my tank with clean water as I am flushing, and of course it is running to waste, then this morning my PH was up, reservoir tank is outside grow room in air condition comfort, conclusion pumps in tank make water warm, warm water makes

PH up. Amen

[RobbieGanjaSeed]

Well I never thought I'd start a debate, I was really having a bit of a laugh when I wrote the first post, not wanting to start a pissing contest on it all..

 

but just how do you conclude

conclusion pumps in tank make water warm, warm water makes

PH up. Amen

?

 

I mean if that's what makes ya happy then take ya amen and raise it to halleluya; and sleep soundly. But are you saying you have a fresh tank of water running to waste and the Ph is on the way up? Man I think someone's in ya house pulling ya chain. The PH would have been high tio begin with, and the water hard, if you used ordinary tap water. maybe you forgot to adjust the Ph in the first place? Like I siad, I've never taken the finer poits of hydropnics overly serious. Just mix this with that, pour in here, press that button, harvest that plant...always been very happy with harvest weights but, which just goes to show how fool proof they've made the nutrient I think. But I have taken water quality very serious fro som eyears in regards to breeding fish and I have never heard of Ph raising by itself overnight with no interference. Not by the mere temps of a pump running in a tank. I'd say ya tank need a good scrub perhaps.

 

I ran over 30 tanks of various sizes for many years..I was always battling the PH on the opposite direction. they were heated, with lamps on them, pumps in them, some had fertalisers in them to encourage plant growth, some had general breaking down of material causing acidicity, and still others were as sterile as could be, with no gravel, no plants, just a lone fish, sometimes two, preparing for breeding.

 

I had pumps running, heaters on, water usually kept around 30 degrees C,and the PH was always on the way down. Never in all those yearsd did I see a tank of water increase in PH overnight for any reason, let alone simply because it ad the "heat" of a pump running in it. What kind of pump u run? A jet engine fuel tanker or something? there shouldn't be enough heat emitting from a small water pump to battle an air conditioned room enough to make the tank warm. Thatr's one hot pump.

 

Using the same one day analogy you've used to work out your conclusion, I have to say my experince is....."pumps and heaters in tanks, warm water makes Ph down. Amen " I'd say that's as positive finding as saying "water pumps make PH rise".

 

I think ya have to look a bit harder than pump made water warm, warm water raises PH dude. If nothing else, I'd have to have made the comclusion Running pump full of saturated salts from years of build up, caused Ph to rise amen. but even then that's assuming you didnt rinse the pump before u started the flush.

I mean even conceding that the PH could rise simply through temperature of water (as opposed to temperature of nutrients even)..I just can't see the pump winning a contest against an air condition unit all night, enough to make the water hot.

 

But that's got absolutely nothing to do with the initial info I was posting anyway, and that was the corelation of Nitrogeon and bi-carb in plant exchange. What would cause water to increase in PH, that has no plants in it at all is something for the x files I think. But sure is beyond the scope of what I was thinking about in relation to the information of theis article on plant growth. Not water keeping qualty.

 

I reckon this professor bloke might know what he's talking about, and it certainly checks with antedotal evidences, but becuase it's a fact that plants take nirtogeon in and let bi-carb out, increasing PH , and the more extreme this takes place, the more extreme the battle will be to control it...never implied it was the one and only way PH could rise.

I just thought it was an interesting discovery that plants relase bi-carb after ingesting N...wasn't meant to be the final answer to Ph problems or anything. Maybe you have know about plants releasing bi-carb into the nute tank for years, but it was new to me and I thought just might have been as interesting to some other person with low knowledge of these things such as myself.

 

Take care man, and maybe buy a smaller pump.

 

rob

[Reverend]

It is rain water and the ph was adjusted.

[RobbieGanjaSeed]

Mn you do have problems. I mean ph adjusted rain water? A run to waste system, aior conditioned room the tank lives in, and a pump is all that's in contact withthe water....and the PH can't be contained?

 

I think you have ghosts mate.

 

Honestly, I just don't understand a lot of this, like why the pump heated the water in the tank, if the tank isn;t under grow lights or in thegrow room, and is in fact even in air conditioning. Something doesnt add up there.

 

Acid rain is unusual in this country, acidic enough to worry about "adjusting" it at least, unles it's the first rainfall after a very prolonged period of dry. I'mthinking you might live where it's been raining for some while, so the OH really should have fallen fromt he sky neutral. Neutral and soft as a babies bum.

 

But ok, so it was acidic , and you have raised it with something alkaline...well that's what raised the PH, you simply added too much alkaline. I can't imagine why it needed adjusting at all but. I haven't tested rain water for a few years, has it gone that far out that we have rain like Europe does now?

 

Anyway, no matter where the water came from, no way did the heat of the pmp throw the Ph out overnight. especially as I keep comming back to, if it was in an air condiotioned room. Withthe water running out of the tank into oblivion, never to be seen again, the water must be constantly being re-introdced. If this is unaduklterated rainw ater, how can the Ph be rising? all I can think of is the tank is needing a good scrub, the pump is chockas with built up salts, or ya Ph meter is fucked. or of course, you have a ghost.

 

Fuck me, you'd be in a right mess if you were actually growing plants in this system, rcirculating it I mean. if ya can't keep it stable in cool, fresh rain water with no plant exchange or nutrients in the tank.

 

What was the Ph before u adjusted it?

 

rob