Is RO water necessary for indoor growing?

[superpedro]

my tap water is around 8.2 so figured I would go for rain/snow instead. any idea about the Ph and ppm on those? Costs for a meter are atm too high and since asking around is for free..

Hey dubite.

It pretty much works like using RO, in the sense it has no or very little buffer.
If you have the correct Ph in the soil when using organics, or a synthetic fertilizer with a good buffer, adding the water won't change the Ph.
You can find trace amounts of nutrient elements in rain, but it depends on air pollution in your area.

Cheers

 

[mtbazz]

Hey dubite.

It pretty much works like using RO, in the sense it has no or very little buffer.
If you have the correct Ph in the soil when using organics, or a synthetic fertilizer with a good buffer, adding the water won't change the Ph.
You can find trace amounts of nutrient elements in rain, but it depends on air pollution in your area.

Cheers

Yeah, but what about nute solutions like earth juice, that cause a dramatic decrease in pH? When I mix my EJ nute solutions the ph drops down to 3.5.

Once I got a ph meter and started adjusting my nutes back to 6.5-7.0, I noticed a positive change in my plants.

 

[Scrogerman]

rain water, as in Natural un-polluted rainwater has a neutral PH 7.0.(I live in the Country)

It would all depend on the ppm's of carbonates in your water(Kh), if you have high ppm water of 250-500++ppms i would consider using 50/50 RO+ to Tap & you'd be good to go! the EC of my Tap is between 1.0 & 2.0(120ppms at .7 con i think?) & has a PH of 7.9-8.4 depending on the time of year ive found, After autunm it seems to increase to 8.4+ & as the year passes by it seems to fall back to 7.9. I use a soft water formula & my PH/ is very stable. I can also use HW formulas with similar results! or so it seems, doesnt seem to make a difference, less phoshate/ph down with HW formulas.

read this it may help:https://www.icmag.com/ic/showthread.php?t=23357


What have you got on chloramines Verdant? ive done a little research & i now believe its completely harmless to life in general at such diluted doses that water suppliers use. i thought like you before i checked it out. still i was getting its harmless/toxic all at the same time! strange stuff.

 

[superpedro]

Yeah, but what about nute solutions like earth juice, that cause a dramatic decrease in pH? When I mix my EJ nute solutions the ph drops down to 3.5.

Once I got a ph meter and started adjusting my nutes back to 6.5-7.0, I noticed a positive change in my plants.

Yes, that is a problem. And that is why I wrote "with a good buffer".

If you have a product made for hard water, it means it isn't balanced around a certain Ph. It's made acidic so you wont have to use too much Ph down, and thereby mess with the NPK ratio.
Mixing hard water products with rainwater or RO won't work.

BTW: super clean RO or rainwater never reads as Ph 7.00, because of the tiny amount of dissolved CO2

 

[Scrogerman]

Yes, that is a problem. And that is why I wrote "with a good buffer".

If you have a product made for hard water, it means it isn't balanced around a certain Ph. It's made acidic so you wont have to use too much Ph down, and thereby mess with the NPK ratio.
Mixing hard water products with rainwater or RO won't work.

BTW: super clean RO or rainwater never reads as Ph 7.00, because of the tiny amount of dissolved CO2

How much bro, its very close to & all the research ive done indicates this, mine shows neutral?
its pollution that gives rain water a ppm value i thought(or at least PH), please correct me?

Its the carbonates in hard water that give it better buffering, RO has No buffering because it has no Alkalinity=no carbonates & a neutral PH. water is like a sponge, it will soak up & release.(saturate)

 

[superpedro]

How much bro, its very close to & all the research ive done indicates this, mine shows neutral?
its pollution that gives rain water a ppm value i thought(or at least PH), please correct me?

Its the carbonates in hard water that give it better buffering, RO has No buffering because it has no Alkalinity=no carbonates & a neutral PH. water is like a sponge, it will soak up & release.(saturate)

What ever gives the water a ppm value has to be a ION, but Ph can be changed without.

Here is a table where you can read the Ph changes in relation to Kh and CO2 (just as an example - don't want to go anywhere with this )

Tab water is(in most cases) alkaline, together with an amount of acid it works as a buffer.
It is the balance between acidity and alkalinity that decides the Ph. If a large amount of both are used, the %balance won't shift as easy = you have a strong buffer.

 

[jammie]

actually one of my projects for this summer will be to install a rain water collection barrel. Did you buy one or make one yourself?

hey there mtbazz- i divert 1 of my rain drain to a 55 gal trash can. i filter it through about 15 layers of cheesecloth attached to the downspout. i use subculture b to protect against any mold or bad bacteria and never have had any problems except in the late spring when pollen overwhelms even the chessecloth. the pollen really screws with your ec readings but my plants don't seem to mind the pollen water. several times a year i flush my gutters with a strong clorox mix

 

[jammie]

rain water, as in Natural un-polluted rainwater has a neutral PH 7.0.(I live in the Country)

It would all depend on the ppm's of carbonates in your water(Kh), if you have high ppm water of 250-500++ppms i would consider using 50/50 RO+ to Tap & you'd be good to go! the EC of my Tap is between 1.0 & 2.0(120ppms at .7 con i think?) & has a PH of 7.9-8.4 depending on the time of year ive found, After autunm it seems to increase to 8.4+ & as the year passes by it seems to fall back to 7.9. I use a soft water formula & my PH/ is very stable. I can also use HW formulas with similar results! or so it seems, doesnt seem to make a difference, less phoshate/ph down with HW formulas.

read this it may help:https://www.icmag.com/ic/showthread.php?t=23357


What have you got on chloramines Verdant? ive done a little research & i now believe its completely harmless to life in general at such diluted doses that water suppliers use. i thought like you before i checked it out. still i was getting its harmless/toxic all at the same time! strange stuff.

i only do 1 grow a year so i don't monitor rainwater ph year round but i don't think i have ever seen our ph much above 6.2ish but it has been as low as 5.5. talk about acid rain!

 

[simos]

RO really isn't a necessity as many have already said. I like to use a chlorine filter instead (small boy) because it isn't as wasteful. If you aerate your reservoir you'll be fine, too. Check your pH every so often and so long as it's below 7.5 you shouldn't have any problems in soil/soilless mixes.

Many people have mentioned rainwater collection, but you should consider how it's being collected... If it's coming off your roof, some kind of filtration unit between the cistern and your rez is probably a good idea given the nasty nature of most common roofing materials.

Bottom line is soil is a lot more forgiving than hydro, and you shouldn't be sweating it too much no matter the source. That said, more control is never a bad thing...

Cheers

 

[Scrogerman]

What ever gives the water a ppm value has to be a ION, but Ph can be changed without.

Here is a table where you can read the Ph changes in relation to Kh and CO2 (just as an example - don't want to go anywhere with this )

Tab water is(in most cases) alkaline, together with an amount of acid it works as a buffer.
It is the balance between acidity and alkalinity that decides the Ph. If a large amount of both are used, the %balance won't shift as easy = you have a strong buffer.

Wow, thanks for this pedro!
Oh i get it! Tecnically rain water should have a ph of 7., but the atmosphere/ co2 etc pollution changes this. i have to get this straight. ions are the carbonates/bicarbonates yes? H2CO3 ---> H+ + HCO3- (bicarbonate ion), its the carbonates in water that gives it its alkalinity & buffer. This is why RO has no buffering cap etc.!

The PH of the rainwater in my area is neutral, it comes out green on reagent liquid PH test(Full spectrum) & on my meter it reads 7 too(my meter doesnt read the units as 7.00, just 7.0.) Im sure this would not be the case if i lived near a City or large Industrial est/area! I suppose it would depend on which way the wind blows too. everytime i check it reads neutral. Id like to actually verify the exact numbers to units, after reading up i see it must have some dissolved solids. Thanks for making me check this out!

Jammie, Thanks for your feedback bro, i live in the hills in the country if that makes a difference! i believe it does. Tested from a bucket outside my backdoor(7)! 5.5 is the bodys skin PH i beleieve. still its low acid rain!
Acccciiiiiiiiddddddd

Thanks Guys Respect!

 

[charliemurphy]

As said before, no, but it is helpful. I know my tap water swings between 5.2 and 7.0 PH, so I have to check and recalibrate at every feeding (thankfully the PPMs are always real low). Using RO simplifies things, but tap waters free

 

[Kcar]

I use RO mostly because I belive that plants have a harder time utilizing the
Calcium carbonate that's in tap. And replace it with Calcium nitrate. Especially
when using coco.

 

[scurred]

Wanna thank the person who started this thread and those who have replied. I bought a RO system a few weeks ago and was planning on using it, I'm from MI and found out my city's water comes from Lake Huron so I am good to go straight from the tap. It reads around 130ppm and 7.2 pH. I think I will keep the RO unit around for flushes and the last 2 weeks of flower. By the way these RO things waste a ton of water, the clean water line puts out a few drops of water every second, but the drain line puts out a constant stream...easily 4x more water going to drain, and the drain water only reads like 200ppm..really inefficient.

 

[Bunz]

Great article how a r/o membrane works and what it removes from your water. Tap water has a bunch of crap added to it that isn't natural. Since we are trying to imitate nature when growing our plants, shouldn't we start off with the lifeblood (water) of every living thing, be as natural as possible. Most complain about the initial cost of a r/o system, however I can say with confidence that most of us have wasted that much on nutes or equipment that is sitting at the bottom of our closets not being used at all.

Never heard anybody who runs a r/o system say anything bad about it.

http://www.islandnet.com/~tiger/Tiger/RO/how_ro_works.htm

 

[potheadmd]

I just started using rain water but have used tap and will continue to when it doesnt rain, peace and overgroe the world.

 

[Sgt.Stedenko]

This ↑↑↑↑↑↑↑

I have a local store I can purchase RO water without even going inside. There is a dispensing machine and I've tested the water. It's perfect for growing. My tap water ph runs 8.5 or higher and the chlorine content is so bad you can't take a shower without your eyes getting bloodshot like you've been in a public pool for 4 hours. It's bad. RO is the only way to go for some of us.

Your eyes have a pH of about 7.5. Your tap is 8.5. The reason you get red eyes is the pH, not chlorine.

 

[Lazyman]

it depends on if you are on city water or well water, and how hard either is to start.

You need RO if:

Your water is over 300PPM TDS
Your water is connected to a water softener
You want to start with a baseline of zero PPM (which is my favorite reason.)

Otherwise, no you don't have to, but I like to start with as low as baseline water as I can, and I also spliced my RO into my fridge for icecubes/water and fill friends water jugs with it too.

 

[Sgt.Stedenko]

If you are running organic, the chlorine in tap can harm the beneficial microbes in the soil.
I use distilled water and cut it with tap I've bubbled for a day or so. RO or distilled water has very little buffer capacity so adding pH up or down can cause wild swings. The buffer capacity of tap water is much greater.
My tap is about 300 microsiemens with a total hardness of 220, calcium hardness of 120, alkalinity of 80 and pH of 7.8.

 

[Lazyman]

Good point about chlorine, I should have added the following:

You DON'T have to have RO to get rid of chlorine, as a Tallboy filter (or bubbling off for 24 hrs) will remove it.

 

[DocLeaf]

My buddy uses RO water

out of 35 people that responded to this post i can't beleive i'm the only one to use rainwater. it has o ppm and the ph is around 6- perfect!

we use rain water in glasshouses often