Is rainwater good for cannabis plants?

M

mykill91210

New Member
spoke to a guy in work he said rainwater is amazing for weed plants its ph balance is perfect for ot, he also said storing nettles and dockleaf in a container with water and storing for a few weeks is an amzing feed aswell , just wondering if anyone could back up what my guy said ?
 
GrowRijt

GrowRijt

Well-Known Member
Rainwater is naturally soft and naturally low ph. It’s great for plants of all kinds and often absorbs nitrates from the atmosphere in small amounts.
 
G

Georgem420

Member
Nettles fermented in water is a great feed. I’ve been feeding my plants this all year. I take a 5gallon bucket , fill it almost to the brim with nettles, comfrey, yarrow, and horsetail, top off with water and let ferment for a couple weeks.
 
xtsho

xtsho

Well-Known Member
Rainwater is water from the sky. It's natures water. Of course it's good for plants.

Keeping a container of nettles, dockleaf, or any of many other plants is a natural fertilizer. It's nothing new.
 
CheGueVapo

CheGueVapo

Well-Known Member
mykill91210 said:
its ph balance is perfect
Click to expand...
it does'nt have any pH buffer capacity... it's similar to RO or destilled.
GrowRijt said:
often absorbs nitrates from the atmosphere in small amounts.
Click to expand...
:rolleyes: small negligible amounts.


xtsho said:
Of course it's good for plants.
Click to expand...
Thats correct.
Some goes for RO-Water... it has low salinity! That leaves space for nutes!
Still it has no buffering capacity.... the pH turns the tide with only little H+ or OH-

Whatever you set that up with alkaline or acid... it adopts the pH of the soil! Because the soil has a lot of pH buffering capacity, the rain water has none.

If you WANT it to increase the pH, you must add liming-agents to the soil, controlling the rain waters pH with just acid or base doesn't make a difference at all.

Using just rain water or RO water reduces the pH on the long term, because it does not contain liming-agents thus the plants still use up calcium and magnesium from the soil.... in result the pH decreases.

So saying "rain water" is Indoors always perfect... specificly regarding pH... is just wrong.

If you do that.... it drops lower and lower.... 5.5 is the run out of liming-agents... if you not have cal/mag defiencies already, then they start when your ph nears 5.5! But whats more worse... lower pH makes phosphorous badly available, so you lock that out first whatever :D
 
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Three Berries

Three Berries

Well-Known Member
My rainwater is around 6.4 pH. I add a cup of well to gallon of rain water. All my initial and seedling watering is straight well water though, 7.4..
 
xtsho

xtsho

Well-Known Member
I don't have any way of collecting any significant amount of rainwater. I've been using tap for decades. Plants don't care. I do use what little rain water I do collect for making JMS though.
 
Three Berries

Three Berries

Well-Known Member
xtsho said:
I don't have any way of collecting any significant amount of rainwater. I've been using tap for decades. Plants don't care. I do use what little rain water I do collect for making JMS though.
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As did I. I suppose with soil that is renewed every grow it's not a big deal. I know with house plants the mineral build up gets pretty bad Some don't mind though.
 
CheGueVapo

CheGueVapo

Well-Known Member
Yes, recycling soil to me is somewhat one of the highest diciple... in return you get ultra low heavy-metal concentration in your flowers. Doing so on the long term requires RO or rain water and keeping the pH balances in desired range and the nutes in balance too, not to let them build up. It works... the organic soils gets BETTER!

I love the reward.... cleaner weed from time to time. In fact the soil is what I care the most... agents, microbes of all kind.... i worry the soil to death instead of the plants... the soil can stand it ;)
 
CheGueVapo

CheGueVapo

Well-Known Member
The pH/limes/RO stuff is easy.

When your pH in indoor pots is too high say +7... you only give rain water without lime or calcium (like from the tap) plus some acid, so it breaks up some cal/mag in the soil and plants consume that....dont expect that decreasing to go fast... it needs time... but cal/mag at those pH is good available, so they suck it down, and after a while it goes down. If not in early vegetation because of the iron-availablity beeing bad that high at 7, then it's not such a big problem at all. SO relax in flowering 7 is not sooo bad, could be worse.... 5.5 in flowering sucks! Phosphorus not available... so important!

You can only fasten that decreasing with a lot of drain! Wasting other nutes!

When your pH in the pots is ideal... say 6-6.4 you dont want to give it rain water perfectly... it's ok for "one cycle" but better add some little lime, about the amount what they consume, like tap, but look carefully, tap sometimes contain a lot too much, check values, soil doesnt require DWC cal/mag ;).... so the pH keeps beeing more stable on the long term, with just some little cal/mag in the water, to slow the decrease of the liming agents.... by that you extend the time you soil liming agents take to use up.

When your pH is to low.... just add some slow releasing liming-agents like dolomite carefully with the water soaking into the soil, they work better than just "OH-" (PH+ bases), that alone doesn't work. But adding the liming agents can qucickly increase the pH.... very quickly... beware!

And because it is hard to remove.... see above, when it is too high... you add carefully during the flowering phase. ;) "Don't knock yourself off" with too much Lime. 6.4 is good for good Phosphorus availability.... im fine with 6.4... 6.7 is great to.... its just not neccessary, and when you want to recycle for another vegetation, this must get down for iron availability again. Thats why i balance lower
 
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CheGueVapo

CheGueVapo

Well-Known Member
The best thing about rain water or RO-water compared to tap water is that it does not contain sodium-chloride. Tap usually contains lot of it and that builds up in the pots at first, because - well it is a nutrition for plants, they need both, sodium and chloride - BUT the demand for EACH is ultralow :rolleyes: , on the other hand they raise salinity greatly, it's fucking table salt.... too much of them and you have the so called "lockout", its gone too salty, cant access anything anymore..... if you add up fertilzers like wormcast or cow-dung to refresh the soil... theres enough sodium-chloride.... you dont need the extra from the tap. It's good for the pipes and we humans are not so sensitivee to it in "smaller" doses.... but think about it. My tap here contains about 1g of tablesalt per 10L... 100mg NaCL per L... im not a fucking laundry mashine, but my kidneys just flush it out. :D. Sounds funny, but my fucking budgy died from it! >:( Kidneystones... Fuck, my organic soil doesn't like drain..... thats why I NEED the RO from the reverse-osmosis membrane! I have no garden to collect my dirty big city rain water.. so thats the best way of keeping NaCl and pulltants out.... It's not a complicated tech.... these RO-membranes are great! Worth investing!

Also for yourself... for your body physysiology it is best to train your gut to absorb nutes from the food, not from the water.... the minerals from the tap are no real "aid" to your nutrition.... water is the media your body uses to flush out too much of anything....but your body is very good with the retention of minerals... it keeps what it needs to keep, you dont lose what you are low on. In fact low TDS water, like from a high mountain river, is the best to drink... if you dont believe me... ask someone from the NAVY.... :) They drink the destilled, the fully desalted (VE), what is said to "suck your minerals dry"... thats BS... eat well, serve your nutrition and minerals by food, and you dont have any problem but very good working organs because the clean water is very good at enabling your kidneys to clean any shit out propperly. :D No shit dude, thats how it works! Just keep the membrane clean from any bacterias from time to time, desinfect them, change the stuff when its meant to be changed, regularly, and the drinking water is perfect, same for the plants.
 
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Nutty sKunK

Nutty sKunK

Well-Known Member
I use it but always add calmag too buffer it. It’s an organic zero N calmag so perfect for flower and veg.

As mentioned above if it’s not buffered with anything it’ll acidify your medium. Also again as mentioned it’s critical to lime the soil. And as I’m learning out the hard way let the soil cook for at least a month. Wet it well and cover in a warm place
 
CheGueVapo

CheGueVapo

Well-Known Member
Resting time is important, to get the microbes back into N-mineralisation, after having initiated "PK-focusing" microbes feeding more PK or even pushing further into that direction with PK-booster-CT.
90% of the nitrogene-reservoir in the soil is the organic substance.
Theres N-immobilisation (fixation) happing. Plants acts dissimilatory in nitrate reduction to the N-pool, while microbes fixate the ammonium in the soils N-pool.
N-mineralisation also happens, that's ammonification and nitrification, when they take from the N-pool.


I know only good german source to describe the processes, have no english at hand sry:
Still it's good material, thank you gov. :)
One thing that you should recoginse it that N can gas out the soil, so when you let it lay tooo long, especially on a organic feed, might add some little N, rewatering with fishmix is nice sometime, (you dont let it dry out but keep it moist), it boost the microbes, enriches the soil, basically with N.... ;) Fishmix is great soil-preparator for vegetation!
 
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Milky Weed

Milky Weed

Well-Known Member
CheGueVapo said:
it does'nt have any pH buffer capacity... it's similar to RO or destilled.

:rolleyes: small negligible amounts.



Thats correct.
Some goes for RO-Water... it has low salinity! That leaves space for nutes!
Still it has no buffering capacity.... the pH turns the tide with only little H+ or OH-

Whatever you set that up with alkaline or acid... it adopts the pH of the soil! Because the soil has a lot of pH buffering capacity, the rain water has none.

If you WANT it to increase the pH, you must add liming-agents to the soil, controlling the rain waters pH with just acid or base doesn't make a difference at all.

Using just rain water or RO water reduces the pH on the long term, because it does not contain liming-agents thus the plants still use up calcium and magnesium from the soil.... in result the pH decreases.

So saying "rain water" is Indoors always perfect... specificly regarding pH... is just wrong.

If you do that.... it drops lower and lower.... 5.5 is the run out of liming-agents... if you not have cal/mag defiencies already, then they start when your ph nears 5.5!
Click to expand...
That’s really cool, I never thought about ph that way. As in soil ph may be able to tell you what nutrients are present/not present. (I know it’s not the case every time) sorry to hear about your bird.
 
CheGueVapo

CheGueVapo

Well-Known Member
To be absolutely precicse, it depends on the "Total organic Carbons" (TOC) too. Look what I've found.
2-Determination-of-the-amount-of-lime-required-to-raise-soil-pH-in-soil-with-a-known.png


Full-text available
  • Jun 2007

Thank you guys! Thats why to start "gently", not directly with a tablespoon per small pot lol, go slow, you can add more, anytime...

PH is always a question of the buffering capacity... from the medium, you want to know whats the "point" of the buffering substances. What buffers in the soil? It's the limes... those say " i dont care your acids, i buffer some H+ for breakfast, im im increasing far higher 7, basta".

The only way is to flush it out, or have someone take the limes for breakfast and reduce calcium magnesium with say rain water or RO in the feed.. then it goes down with your plants eating it for breakfast. :) That you must be aware of when feeding rain water, RO... thats causing it to use up and PH go down.

The trick is to balance these liming buffers to the range were all nutes all available best. This knowledge about them, and how to affect the pH with them, relieves you from the stress measuring drain and flooding acids and scream "WTF, soil, obey, why don't you" :D

Also it's not hard to balance other nutes... cannabis just sucks more whats more... and balances, hard to get it out of control, when you got the lime in control.... and the N in the flowering. Doh! ;)
 
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puck1969

puck1969

Well-Known Member
CheGueVapo said:
The best thing about rain water or RO-water compared to tap water is that it does not contain sodium-chloride. Tap usually contains lot of it and that builds up in the pots at first, because - well it is a nutrition for plants, they need both, sodium and chloride - BUT the demand for EACH is ultralow :rolleyes: , on the other hand they raise salinity greatly, it's fucking table salt.... too much of them and you have the so called "lockout", its gone too salty, cant access anything anymore..... if you add up fertilzers like wormcast or cow-dung to refresh the soil... theres enough sodium-chloride.... you dont need the extra from the tap. It's good for the pipes and we humans are not so sensitivee to it in "smaller" doses.... but think about it. My tap here contains about 1g of tablesalt per 10L... 100mg NaCL per L... im not a fucking laundry mashine, but my kidneys just flush it out. :D. Sounds funny, but my fucking budgy died from it! >:( Kidneystones... Fuck, my organic soil doesn't like drain..... thats why I NEED the RO from the reverse-osmosis membrane! I have no garden to collect my dirty big city rain water.. so thats the best way of keeping NaCl and pulltants out.... It's not a complicated tech.... these RO-membranes are great! Worth investing!

Also for yourself... for your body physysiology it is best to train your gut to absorb nutes from the food, not from the water.... the minerals from the tap are no real "aid" to your nutrition.... water is the media your body uses to flush out too much of anything....but your body is very good with the retention of minerals... it keeps what it needs to keep, you dont lose what you are low on. In fact low TDS water, like from a high mountain river, is the best to drink... if you dont believe me... ask someone from the NAVY.... :) They drink the destilled, the fully desalted (VE), what is said to "suck your minerals dry"... thats BS... eat well, serve your nutrition and minerals by food, and you dont have any problem but very good working organs because the clean water is very good at enabling your kidneys to clean any shit out propperly. :D No shit dude, thats how it works! Just keep the membrane clean from any bacterias from time to time, desinfect them, change the stuff when its meant to be changed, regularly, and the drinking water is perfect, same for the plants.
Click to expand...
I collect rain water in a 250 gallon tote but the ph is 9 when I test. I know it’s not really 9 it’s just picking
Up the limestone from my shingles on my roof. That being said my plants still get locked out by the end
of the outdoor growing season. Question is, what could I do to seal the part of my roof that I collect water
from or can I add something to the water to adjust it? I have added lemon juice before with little success.

My tap water is very hard so this is why I have been collecting water. The picture is from 1.5gallons of water
that I boiled off.
 

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simpleleaf

simpleleaf

Well-Known Member
mykill91210 said:
spoke to a guy in work he said rainwater is amazing for weed plants its ph balance is perfect for ot, he also said storing nettles and dockleaf in a container with water and storing for a few weeks is an amzing feed aswell , just wondering if anyone could back up what my guy said ?
Click to expand...
I have no comment on nettles or dockleaf. Rainwater is very good from a mineral standpoint but have you heard of acid rain? There are a variety of pH ranges given for rainwater, but 5.6 pH is a commonly cited value, which is a little too acid even for hydroponics. I would definitely pH it.
 
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