Why we use distilled / RO water

[lysol]

So I've been mixing like 3ml of FF grow big to 4 gallon of water, by the time I PH down I'm up to 250ppm when I want to stay <= 200ppm, my seedlings are frying as a result. My tap starts at 150ppm, I did an experiment and just plain PHd tap water comes in at 200ppm.

I am using general hydro solid form PH down. Is it normal to see 50ppm come from your PH solution? I guess this is why people use distilled? I am off to buy a bunch and try it out. I just need to use distilled while they are little right?

Oh and the growbig says it contains calcium as well as magenesium, when I use distilled water will I be omitting anything important. Freezerboy I seem to remember having said the nute companies expect you to use tap water and if you use RO / distilled you have to add back what is missing, welll I dont know whats in my tap but its taking my damn ppm too high to grow a healthy seedling. Do I need to mix tap + distilled? I would rather use the most pure distilled water for my fragile seedlings as long as they don't need the liquid rock from my nasty tap

I'm about to sprout a sativa and hear they are even less hungry so an answer will be helpful. Also what do you guys usually start your ppms out at? I read somewhere 400 but that was frying it I'm down to 250 and still coming out with burnt new growth for the past week, I'm at 4 nodes of a big bang feminized seed if you were wondering.

Just trying to get my facts str8 so I act on accurate information.

 

[Guest 18340]

What brand nutes you using?
150 ppm tap is'nt too bad.

 

[Kelly.]

....

 

[lysol]

Ahh FF = foxfarm ( growbig )

150ppm isnt too bad in theory but this strain is sitting here burnt on 250ppm, cant argue with the seedling! The highest I went was like 350ppm and that was last week. I add nutes, the truncheon meter has a resolution of 50ppm, so I add nutes to 200ppm, then I'm at like 6.8ph, I PH down to 5.8 and I'm at 250ppm again

I just picked up some distilled water, cant beleive walmart didnt sell it ( walgreens does ). so... do I just add nutes PH and go or do I need to put half tap to have sufficient levels of calcium / magnesium?


Growbig has: 3% N
p205 2.0%
k20 6.0%
Ca 2.0%
Mg .5% ( .5% water solluable )
B .02%
Cu .05%
Fe .1%
Mn .05%
Zn .05% ( .05% chelated )

Also I just noticed on the bottle it says when plants show preflowers to switch to big bloom, well big bloom is basically just N and no other minerals, for that youre supposed to use tiger bloom, foxfarm sure does want you to buy up the nutes

And I guess the truncheons way of showing 0 ppm is to do nothing, they should totally make an extra indicator for 0ppm so people dont think their meter is broken lol

OK Another question
Im mixing my new solution right now, I added 3ml of the grow big again and PH dropped from 7.5 to low 5s ... scratch that... 4.2 ( almost a 3 point drop from less then 1ml per gallon? ), when I had the tap water that amount didnt budge the PH and I needed like 1/4 teaspoon + of the PH down ( a lot ) to get the PH down to the 5s

Does my tap water have some kind of buffer?

I think this distilled water is going to be really friendly for my MJ

 

[bigjay]

Distilled water is the same as letting your tap water sit uncovered for 24-48 hours. Ya dig>

 

[Guest 18340]

Yeah. You need R/O water. Look on the bottle and it should say something about reverse osmosis.
I use GH flora series and R/O water (25ppm) from a machine in front of the local WinnDixie and don't ever need to add cal/mag.

 

[lysol]

Yeah. You need R/O water. Look on the bottle and it should say something about reverse osmosis.
I use GH flora series and R/O water (25ppm) from a machine in front of the local WinnDixie and don't ever need to add cal/mag.

Yeah to which question? So the cal + mag in my nutes are not sufficient I need to add another 25ppm of cal + mag or use RO water?

Distilled water is the same as letting your tap water sit uncovered for 24-48 hours. Ya dig>

Distilled water is the same as letting your water sit out and collecting just the water vapor on a slanted glass pane above the body of water, allowing the condensation for the water vapor to roll off the slanted pane into another collection bin. That is how it is produced. I am open minded but I'm pretty sure evaporation does not work like that. http://en.wikipedia.org/wiki/Evaporation If you could produce distilled water by leaving water uncovered, welll.... thats how we would produce it, but we dont because it dont work like dat ( http://en.wikipedia.org/wiki/Distillation ). If you want to test that boil a gallon of water for an hour and measure ppm before and after. You should see an increase because the evaporating water leaves behind solids. If the solids evaporates as well, then distillation would not work. If you are right then I'll shit bricks because apparently what I learned in 3rd grade is wrong :-( lol

You were probably confusing solids with gases, chlorine is a gas so you can diminish the clorine to "safe" levels by letting it sit out, but solids cannot and do not evaporate, gases do/// w\hen I let my tap water sit out I get white crud all over, those are the solids that were left behind from the water.

 

[Oldmac]

Distilled water is the same as letting your tap water sit uncovered for 24-48 hours. Ya dig>

No it is not. Ya dig?

 

[BowlPacks]

No it is not. Ya dig?

Thank you...
Lets all get out our textbooks, kidds

 

[Oldmac]

Hello lysol,

You do not need to add cal/mag to RO or distilled water if your nutes contain them. You also don't need to add cal/mag if you where growing in Pro-mix, which contains dolomite lime and that gives off calcium and magnesiun when it breaks down. All other times cal/mag is a necessity.

When rooting cuttings or starting seedlings you do not need any nutes at all. And when you do start to feed them, less is more at the begining.

You may find using distilled water for just the first few weeks will help you alot, and then you can revert to using your tap water after that. You may not need to go to a RO filter system at all. For $200 for the cheapest RO and closer to $400 for something like a Merlin, you can buy alot of distilled water for those first few weeks that you really need it.

Good luck, hope this helps.

 

[lysol]

Word x3.

Yeah my time installing the shit would cost me more then the unit. I can pickup water cuz im at the store anyways. I figure itll help when before 75% of my solution was unusable!

Should I root cuttings in distilled?

Would an investment in a meter more accurate then 50ppm pay off in your opinion?

Distilled took me 2 minutes to prepare ec and PH, tap water took me 20m cuz I had to keep adjusting and waiting, distilled water is like a blank canvas, like when I added ppm it dropped so many points vs the tap, what causes this? Is EC logarithmic?

 

[Oldmac]

Word x3.

Yeah my time installing the shit would cost me more then the unit. I can pickup water cuz im at the store anyways. I figure itll help when before 75% of my solution was unusable!

Should I root cuttings in distilled?
Yes. You can add something like Olivia's clonning solution (less then is even recommended). I use 200ml of Olivas to 6 gal of water in an EZ-cloner 120.

Would an investment in a meter more accurate then 50ppm pay off in your opinion?
Probably cause at some point you will want to check the run off or your rez to see how much nutes are being consumed. I personally use a meter that reads PPT (parts per thousand) just because it is so much more accurate. (slight pain to convert mfg suggested ppm to ppt)

Distilled took me 2 minutes to prepare ec and PH, tap water took me 20m cuz I had to keep adjusting and waiting, distilled water is like a blank canvas, like when I added ppm it dropped so many points vs the tap, what causes this? Is EC logarithmic?
Well already you see an improvement over tap! The whole reason to use RO (or distilled) is to strip everything out of the water and add back just what is needed. Plus there is no need to guess at what is making up all that ppm too begin with. Not sure if EC is a logarithmic function, the only way I can convert ec to ppm is to use a chart.

. Oldmac

 

[FreezerBoy]

My water has an EC of 0.5 (250-350 ppm) 150, as a number, is nothing to fear though I suppose "what" the 150 is made of could be.

I don't measure EC of my starter solution which is 1.25 ml per gal each GH FloraMicro and FloraBloom.

I have to admit never growing with RO and my statements about it are based on my readings here, rather than hands on.

 

[lysol]

Alright good stuff, freezer I suggest trying it, that seedling was burning on 50ppm of nutes added, with the distilled I crammed a full 150ppm down it's throat and its definitely responding fast no tip burn on new growth. Im finally starting to "read" my plants,

and just for laughs.... https://www.ezoetic.com/p-48-waterwise-model-1600-continuous-collection-kit-3-gallon.aspx

or if that is too small for ya

http://www.aquatechnology.net/high_perf_distillers.html

I hear FL is basically all lime stone underground, could be why I was having a hard time PHing down before

 

[Wait...What?]

its not about raw numbers as plants tolerate a range of values
its about ratio and proportion
i have kickass tap water but the Ca is too high and it throws off the N:Ca balance which ends up locking out Mg
N:K
N:Ca
Ca:Mg
are important ratios when growing plants

 

[lysol]

I stumbled on some info explaining the difference in PH adjustment needed between tap water & RO / distilled.
http://www.flairform.com/hints/ph_alkalinity_CO2.htm

The pH of water rarely indicates how much acid or alkali is needed to change the pH.

For example: It is not uncommon to have 2 different samples of water of ‘equal’ pH where one requires 4 times more pH adjustment than the other!

This phenomenon is due to the concentrations of ‘bicarbonate’ and ‘carbon dioxide’ present in the water. It is particularly pronounced with bore waters.

Bicarbonate

Bicarbonate (HCO3-) is alkaline and therefore elevates pH. Its concentration is normally expressed as “alkalinity”. It is one of the main factors causing pH to rise in nutrient solutions and also confuses growers in their attempt to estimate how much pH Down will be required to lower pH.

Unlike ‘hydroxide’ (i.e. common ingredient for pH Up), bicarbonate is only weakly alkaline and therefore unable to elevate pH above ~8.3, regardless of its concentration. As a consequence of this, unlike hydroxide, bicarbonate has a strong pH buffering capacity which means it resists pH change when acid (pH Down) is added. For example, a weak solution of hydroxide can have a pH of 14 whereas a bicarbonate solution 10 times more concentrated has a pH lower than 8.3! Now, the interesting fact is, to lower the pH down to 4.5 the bicarbonate solution requires ~10 times more acid than the hydroxide solution - even though its initial pH was so much lower.

Hence the presence of bicarbonate is deceiving because unlike hydroxide it is not detectable from pH readings and is only noticeable once you attempt to lower the pH.


Carbon dioxide

Ever wondered why pH fluctuates (i.e. typically upwards) after it is lowered? This behaviour is actually a consequence of adjusting the pH. Lowering pH via adding acid, removes bicarbonate and produces carbon dioxide. The presence of this free (i.e. uncombined) carbon dioxide (CO2) tends to lower the pH because it reacts (only weakly) with water to form carbonic acid. However, CO2 concentrations above about 0.5 mg/L in water are unstable when such waters are exposed to the atmosphere (at sea level pressures). Under that condition CO2 in excess of 0.5 mg/L will slowly escape from the water into the atmosphere. Consequently this loss of acidity causes a corresponding rise in pH.

This subsequent rise in pH is particularly noticeable with ground waters (i.e. bore water) which typically have CO2 contents around 50 - 200 mg/L (due to biological activity within the aquifer). When these waters are pumped to the surface, the pH rises with time because the excess (acidic) CO2 gradually escapes (Fig 1.16). The pH will then rise to a stable value solely dependent on the water's bicarbonate content.

Example: A bore water with 100 mg/L bicarbonate and 100 mg/L of free CO2 will have an initial pH of 6.3. Its pH will gradually rise to 8.2 after it has been exposed to the atmosphere for sufficient time to allow the CO2 content to drop to around 0.5 mg/L.

The same phenomenon (although to a much lesser extent due to lower CO2 contents) can occur with scheme (tap) water. Thus the conclusion – because the pH of waters is only stable after aeration, it is only the "after aeration" pH value that has any interpretative significance. To determine that value, aerate the water by tumbling a sample of it from one container to another, 30-40 times prior to measuring its pH.


Conclusion: Interpret pH values with caution because a water with a lower pH than another may produce the higher pH after both are aerated!!

 

[delta9nxs]

Hi, lysol

great article you posted, i've got it in my documents.

You definitely need a ro filter. I have 200 ppm tap water and struggled trying to grow using it. Although an analysis showed that it was primarily full of calcium and magnesium, it was not available to my plants because they were both in carbonate form. I'm not a chemist but it seems that in that form their molecules are too large to pass into the root hairs. Then they block the pathways so that the usable forms cannot pass through, causing partial and sometimes full lockouts. So, even though your nutes may show an ample supply of cal-mag, the plants can't take it up.

Btw, you may be already thinking, like I did, “my tap water works great outside on the tomatoes and cucumbers, but not on my cannabis being hand watered in pots of inert medium”. The reason is the microherd. They chelate the calcium carbonate and magnesium carbonate into forms your plants can use. Indoors you are not going to have the same microbial population density or the time for conversion.

With ro water you have a known starting point every time. No antagonisms to deal with.

Almost all the top nute manufacturers tell you their product contains enough cal-mag, or, like botanicare, instruct you to add their version at their dose. Although theoretically it is just enough for most plants, cannabis needs a lot of calcium. Most of the problems indoor growers have are related to calcium. It is critical in every stage of growth. I believe that cal-mag levels in most nutes are borderline at best, with the plant being on the edge of deficiency most of the time and actually going deficient from time to time dependent upon growth rates or running continuously deficient dependent on strain.

When I started supplementing cal-mag regularly I began seeing fewer problems. Both growth rate and yield went up.

It takes 1 level Tbs rite-aid epsom salts to make 100 ppm magnesium sulphate at the .5 conversion in 20 gals ro water.

4 tsp fertilome or greenlight tomato blossom end rot treatment (calcium chloride) makes 100 ppm in 20 gals ro water.

Top off with about 600 ppm of whatever high quality nute you're using and adjust ph upward to wherever you start at and you should end up, using ro water, at between 825-850 ppm. Ec 1.65-1.7. you will not need ph down in ro water.

 

[Biscut Eater]

The great thing about using RO water is if you run into problems....you know it's not the water. The few bucks spent is worth the trouble shooting procedure when you do have problems. Just my opinion...

 

[lysol]

@12 nodes and 100ppm and still burning the sheeeet out of em. I started a sativa on 100ppm of nutes and burnt it too, just running straight distilled on that one.

How is it 100ppm of nutes w/ distilled water burns a 10 node tall plant when half the people's here tap water starts at 250ppm? By the time they add nutes theyd be at 300ppm. I am positive its nute burn the tips on new growth is white and purple hues in the leafs, the roots look thinly and dying, if I dilute it down below < 100ppm new healthy ass white roots grow, if I dont keep it at <= 100ppm it fries and the plants almost half a foot with 1" side branches now, what gives?

Picky strain?
Cursed RO water?
Bad Meter?
Not really overnuting?

I change out completely like more frequently then 1x a week. Just plain tap water burns the crap out of the seedlings / small plant. The PH spotting is because overnight I got a drift into the high 7s, the tip burn and leaf curling was way before that and is still happening. I cut off the lower fans they were turning white yellow from PH. If you look carefully you will see tip burn though, I recently diluted so the newest emerging leafs arent that bad but I know if I let it hit 150ppm itll start frying again. theres this purple hue from the back of the emerging leafs that is distinct to overnuting from what ive seen

Since I'm starting with a "blank" slate and adding back nutes I would hope the ratios are correct. For the sativa seedling I dropped nutes until the meter registered a reading ( 100ppm ) and it fried overnight like that. I dont know what else to do, ... besides measure 1gal to 100ppm and then dilute it down 4x to know I have 25ppm? Do I *need* a more accurate meter or am I doing something else wrong

delta9 = and YES I am needing lots of PH down even with the RO water. ( it drifts up ).

http://www.icmag.com/ic/showthread.php?t=122162&highlight=dwc this guy starts his seedlings at 2.2 ec, why cant mine take 50ppm below freaking tap water?

Links to relevant diaries / journals appreciated

 

[Wait...What?]

Underfertilized looks very much like overfertilized. Given your nutrient strength, what makes you think they're burning? I don't see fert burn in your pics.

When your mix is way too hot, it'll look like acid melting the leaf [frost damage looks similar]

When its just somewhat hot with too much N, you'll see eagle clawing [which is not what is in the pictures above this post] and it really means you need more light, not less N.

Your plants look short on K, but take anything I post with a grain of salt as I'm just some schnook on the internet and you're the one doing the growing...