Water Question, RO, Distilled, pH

In the past month, I read a lot of new posts from growers having a pH problem, of the pH going from an adjusted 5.8 at night, just to spike back up to 7.0 by in the morning.
There were two common things I noticed. Half of them were using a nute-soup, or a mix of three to 6 different things in their water. They would have a VEG nute, or maybe two different VEG nutes, a catalyst like Liquid Karma, some Cal-mag supplement, some Hydrozome, some pH Down, some peroxide, etc, etc etc, and I could easily blame the pH spikes on the nute soup they had mixed.

BUT

I also noticed that over half were using R.O. water or Distilled Water. When I started researching pH, I read up on Buffers and Stabalizers, and the fact that water has to have something in it, like some minerals, or solids, to buffer or stabalize the pH or the pH will spike rapidly up and down.

I saw a couple of posts from Filthy Fletch about this, he's a knowledgable, experienced well-read grower. He seems to be really down on R.O. water or plain pure distilled water.

Does anyone know anything about R.O. water and Distilled water NOT being the best to use in Hydro because of pH problems?

Does anyone have any cut and paste articles or links to, or experience or some FACTS about R.O. water and Distilled water NOT being good for pH and Hydro growing?

Any info on Buffers for pH?

great ? roseman . hope this gets some feed back because my ro machine brings my ph down to 4.3 and most people i talk to say theirs is in the mid 5s

But using R.O. water, will it stay stable or spike up often?

Is R.O. water more difficult to maintain the pH , or easier?

im still new to this but when i adjusted my ph at 5.7 it stayed the same till i added hygrozyme then it jumped to 7.2 within 10 mins

southern homegrower said:

im still new to this but when i adjusted my ph at 5.7 it stayed the same till i added hygrozyme then it jumped to 7.2 within 10 mins

Click to expand...

Hygrozyme? - Messes with pH < a link

I find much greater stability in RO water. My tap water is about 380 PPM, mostly calcium I presume. It's very alkaline, over 7.8 and remains so after RO filtration, although the PPMs go down to 15. If I add nutes to tap water, it spikes within an hour or two back up to the original levels. The RO water does not do this. So I usually add Barricade to get it to 5.8-6.0. Where it stays. I have my own machine now, but used to buy from the culligan dispenser in the supermarket. That's usually around 50 ppm; I guess they put some minerals back for taste?

I used to use Hygrozyme. I ran out and never looked back. pH spiking from it could explain some past problems.

I will see if I can find any write ups on the topic but from my own expirence and talking to growers i have been around since starting we all have ended up with the same results. The RO or distilled water always seemd to not hold a steady ph it was fine by ittself but once nute went in it was an hourly to daily adjust. The oppsosite seemded to happen with regular tap water. My own tap water is right around ph 7 with a ppom of about 100. I also had a free city water test done to just kind of get the readings. What i was seeing from this was there were trace amounts of micro elements that actually a plant needs which are not in RO water as the RO removes these minerals the plants like. The chlorine levels in my tap water were very minut and are easily evaporated in a day. If i place my water in a res and then add my nutes stir and let sit an hour then take my ph and make adjustments to 5.5 using granulated pool ph minus or up I find the ph stays the same up until I can see a visable decrease in my water levels which is about 2 days but then the ph will barely peak 6. I do have to say i have been sticking to my Foix Farm nutes with additives from Humboldt county, nitrozyme,botonicare sweet, and grotek super H202 and dont get the rise. i do hear alot of ph issues as in regards to moving using Flora nutes, Biobizz, and powdered nutes. from reading and talking I do belive alot has to do with the ph buffers in either your water or nutes. RO water strips the added ph buffers from municiple water in the RO process which then leaves the watre without minerals and buffers so you have a purr water but its now incomplete while un touched city water has the buffers and micro elements. Some nutes now offer a pre mixed ph buffer in the nutrients them self to help keep levels from spiing. The new Advance Nutrients which i havent tried yet are built to be simple and ph self adjusting which Im interested in seeeing in action. They add ph buffers and stabalizers to the mix that all a preestablished ph value to be maintained. The bases of my preference to not use RO water has been through the years of trying it and finding growers in my circle all having similar results between it and tap water. I no longer know anyone personally who uses RO water to grow so I think this may prove some kind of issue with RO when so many left it and I see so many on this site alone have the same issues my group had seen in years past.

Fletch, Interesting you should mention Humbolt because I just talked to a tech support guy at Humbolt Nutrients and he says that using RO water and their 3 part there should be little pH swing UNLESS there is organic matter being put in or getting in to the res. Of course everyone selling products says buy ours and your problems will be over so I don't know.

FilthyFletch
Mr I Can Do That For Half
Mr. Ganja

THANK YOU,

Man, that was exactly what I was looking for and expected to hear. So many growers argue about needing PURE water with NO minerals in it and using Distilled water and RO water and then I see them bitch about pH spikes and not being able to maintain the same pH level for a entire day.

I am seriously coming to believe that water ahs to have something in it, a buffer, a stabalizer, to maintain and jeep a level pH. Yea, I know eating the nutes makes the pH go up and down, but not in a whole 1 point in a day, from 6 to 7 or worst.

If you or anyone can find any scientific writing or article to link to about Buffers, I sure would appreciate it.

Roseman said:

But using R.O. water, will it stay stable or spike up often?

Is R.O. water more difficult to maintain the pH , or easier?

Click to expand...

My friend is a noob grower using RO water in DWC buckets. He had read about ph problems with RO water prior to starting, but he has been pleasantly surprised. His RO filter gives water with a ph of 6.9-7 and a ppm of about 10. Using Canna Nutes, Cal-Mag at 1/2 dose, and GH PH Down his ph stays stable for days (it slowly rises but if set to 5.5 it will stay below 6 for at least 2-3 days).

This should be simple enough for anyone to follow:

http://en.wikipedia.org/wiki/Buffer_solution

I use distilled and mine only varies a little from 5.8/6.0 thats it

Mindmelted said:

I use distilled and mine only varies a little from 5.8/6.0 thats it

Click to expand...

Must be those Humbolt nutes you use I have to think that if tap water just happened to have the right level of the right buffers for growing marijuana in hydro it would be an accident. And it might be different next week or next month. Starting with zero water seems like less of a roll of the dice.

Illegal Smile said:

This should be simple enough for anyone to follow:

http://en.wikipedia.org/wiki/Buffer_solution

Click to expand...

this part had me confused for a second:



[edit] Buffer capacity


Buffer capacity for pKa=7 as percentage of maximum
buffer capacity = where dn is an infinitesimal amount of added base and d(pH) is the resulting infinitesimal change in pH. With this definition the buffer capacity can be expressed as[3]

where Kw is the self-ionization constant of water and CA is the analytical concentration of the acid, equal to [HA]+[A-]. The term Kw/[H+] becomes significant at pH greater than about 11.5 and the second term becomes significant at pH less than about 2. Both these terms are properities of water and are independent of the weak acid. Considering the third term, it follows that

1. Buffer capacity of a weak acid reaches its maximum value when pH = pKa
2. At pH = pKa ± 1 the buffer capacity falls to 33% of the maximum value. This is the approximate range within which buffering by a weak acid is effective. Note: at pH = pKa - 1, The Henderson-Hasselbalch equation shows that the ratio [HA]:[A-] is 10:1.

LOL,,just kiddin!!

Illegal Smile said:

Must be those Humbolt nutes you use I have to think that if tap water just happened to have the right level of the right buffers for growing marijuana in hydro it would be an accident. And it might be different next week or next month. Starting with zero water seems like less of a roll of the dice.

Click to expand...

I havent used the humboldt nutes yet but they are on my list of next to try. i use thier additives but the nute line just got full avaliable to me...see I have used my water sources for years same taps and the levels dont budge much at all out the tap and all sources seem to maintain same ability to hold the ph they are set. Ill do a mini expirement and see what happens I will use 2 5 gallon buckets and fill one with RO water and 1 with tap. i will record ph and ppm right then. i will then add a week 4 nute mix to each and then ph both to 5.5. I will then set them aside and each day for 2 weeks check the ph and ppm of both and see if there is a differenced in each bucket. This will let me see exactly if one or the other is more prone to flux...The water being at zero ppom doent really mean its better to me it actually means the oppsosite as now you may need to add calcium or nitrates to get it back to stage 1. Ill get a little time and post the mini expirment as soon as I can and just see if it does anything like that

FilthyFletch said:

I havent used the humboldt nutes yet but they are on my list of next to try. i use thier additives but the nute line just got full avaliable to me...see I have used my water sources for years same taps and the levels dont budge much at all out the tap and all sources seem to maintain same ability to hold the ph they are set. Ill do a mini expirement and see what happens I will use 2 5 gallon buckets and fill one with RO water and 1 with tap. i will record ph and ppm right then. i will then add a week 4 nute mix to each and then ph both to 5.5. I will then set them aside and each day for 2 weeks check the ph and ppm of both and see if there is a differenced in each bucket. This will let me see exactly if one or the other is more prone to flux...The water being at zero ppom doent really mean its better to me it actually means the oppsosite as now you may need to add calcium or nitrates to get it back to stage 1. Ill get a little time and post the mini expirment as soon as I can and just see if it does anything like that

Click to expand...

if you do that experiment, I will ask you if I can copy it into a book.

sure can so if thats what you kinda have plan ill make sure to use good phtos and descriptions and will watch my horrid spelling and run ons for ya lol Ill also pm ya as I make the thread so you can have it handy

FilthyFletch said:

I havent used the humboldt nutes yet but they are on my list of next to try. i use thier additives but the nute line just got full avaliable to me...see I have used my water sources for years same taps and the levels dont budge much at all out the tap and all sources seem to maintain same ability to hold the ph they are set. Ill do a mini expirement and see what happens I will use 2 5 gallon buckets and fill one with RO water and 1 with tap. i will record ph and ppm right then. i will then add a week 4 nute mix to each and then ph both to 5.5. I will then set them aside and each day for 2 weeks check the ph and ppm of both and see if there is a differenced in each bucket. This will let me see exactly if one or the other is more prone to flux...The water being at zero ppom doent really mean its better to me it actually means the oppsosite as now you may need to add calcium or nitrates to get it back to stage 1. Ill get a little time and post the mini expirment as soon as I can and just see if it does anything like that

Click to expand...

This is a good idea and I am currently doing the same thing, although with just one gallon and my AN nutes in seedling doses. But no matter what it shows, it doesn't mean everyone should stop using RO water and start using tap water. If anything it will mean that a few of us have tap water that, at certain times and conditions, seem to act as a useful buffer making pH tend toward the high 5s.

I keep recalling what I read that buffers work within certain pH ranges. Some tend to stabilize at 8, some 7, some 6 and some 5. The odds of someone happening to have tap water that just happens to have exactly the right level of impurities that buffer pH to where we want it has to be pretty small. And if there is such a mix of whatever, why isn't someone selling it? Fletch, maybe you can extract the sediment from your tap water, market it and get rich!

edit: I went ahead and started this test and i'm stunned! I started with a gallon of distilled and a gallon of tap. They both tested at 7. I added the nutes and they both still were at 7. One ml of pH down brought the distilled down to 5.7. BUT it took I don't know how much to bring the tap water down, it wanted to hug 7. 4 ml only brought it down to 6.8! I started pouring it in and got it to 5.7. This tells me my tap water has some powerful buffering, but it wants to stay at 7. This would be bad water for me to use. I'm going to check for drift every few hours but I'm not sure I see what would cause any drift since there is nothing organic going on, no rockwool, no plant.

I'm guessing the dissolved solids in the water will continue to buffer the water until it's back up to close to its original state.

I was reading up on buffering solutions yesterday, inspired by this thread; you are right, specific solutions buffer to specific pH ranges. Wondering how this could be exploited commercially. Nope, I'm not qualified, lol.