Is Reverse Osmosis necessary?

[Nifty_PoT]

With water that hard (.7 EC ) that faucet filter wont do much . Your best bet would be a cheap 50GPD 5 stage RO system.

 

[Douglas.Curtis]

This is also kind of my worry. That if I do get an RO system, it would be nothing but more of a hassle. Also I'd probably only end up using it for the last 3-4 days of flush But if enough good growers in this thread say they couldn't live without. id definitely try it out.

I would suggest getting a larger than 50gpd unit, you'll be surprised how useful it is. Everyone in my house drinks r/o including the animals, we cook with it and I find other uses where clean water is preferred over >14ppm water.

If your plan is to only use r/o the last 3-4 days, I'd skip it entirely, because it really won't matter at all. Kinda like spraying a dirty wall with a little spray bottle. That soil is caked on and won't be coming off with even a high pressure hose.

 

[Terppalooza]

It really comes down to what quality cannabis you're intending to grow.

Superior Quality? You're going to want to know exactly what is in your water, and you'll want to remove anything cannabis does not convert to plant products.

Poundage for Sale? Anything 150ppm or less is going to pass the average user test. I figure 90% of the planet has yet to experience quality cannabis anyway, and 50% of the population has an 'average' or lower ability to taste and smell. This leaves a huge margin of error for the 'marginal' quality cannabis. (haha)

Not knowing what quality cannabis is like makes for a lot of misinformation in the community. Some of the more glaring representations are...

- Drying your cannabis bone dry for storage does not hurt the quality
- Water quality is less of a concern than pH/ppm
- The history of the soil you're growing in does not matter
- Boveda/Silica-Gel packs do not affect cannabis
- Hot/Wet grows great cannabis
- You can flush out overfeeding

and on, and on, and on.
I'll get off my soapbox now, because it gets old after a while. Let's just say I want more growers to work on widening their awareness about cannabis quality. Sharing a bowl of your cannabis with me shouldn't hurt my lungs. The description of my experience from smoking it should not hurt your feelings.

There was a lot of reasonable stuff said in this thread. You definitely convinced me. I grow because I want the best nothing else. I just ordered a 50GDP RO system and will use that for the flush!

So here comes my next question where I live chloramines in the water are banned. and really no detectable amounts of chlorine, everyone drinks tap water here. So would you really see a benefit in always feeding your plants (while not flushing) using RO water? Beacause im planning it only only using it during the last week of flush

 

[Terppalooza]

I would suggest getting a larger than 50gpd unit, you'll be surprised how useful it is. Everyone in my house drinks r/o including the animals, we cook with it and I find other uses where clean water is preferred over >14ppm water.

If your plan is to only use r/o the last 3-4 days, I'd skip it entirely, because it really won't matter at all. Kinda like spraying a dirty wall with a little spray bottle. That soil is caked on and won't be coming off with even a high pressure hose.

just saw this reply. well concidering my tap water is resonably clean. waht woudl be the minimum ammount of time you use RO water? or simply always. or nothing in your opinion? ill probaly be comparing it to see myself in the future myself aswell

 

[art.spliff]

Sand Media Filters Removal of Solids Down to 20 Microns Yardney Industrial

 

[art.spliff]

What Is a Biological Wastewater Treatment System and How Does It Work? April 1, 2019 Samco

 

[Douglas.Curtis]

just saw this reply. well concidering my tap water is resonably clean. waht woudl be the minimum ammount of time you use RO water? or simply always. or nothing in your opinion? ill probaly be comparing it to see myself in the future myself aswell

Unless your tap water is under 14ppm all the time, 100% R/O, all the way through till harvest. When the tap water is up around 150ppm or more, I can accurately pass the pepsi test (blindfolded) and sort 100% r/o grown/flushed, vs. Tap water grown, r/o flushed, vs. tap water grown/flushed flowers by smoking samples. Same room, all the same strain, same pH levels, only difference was starting water.

Should you decide to use tap water, your 'learnin' of growing will be specific to how your tap water pH changes with your setup. Should you later move (even only a few miles away), your chances of having different tap/well water is very good. What worked before has no guarantees of working again. With r/o, it's always the same results from the same inputs time after time.

If it didn't make such a big difference I would let it slide. As it is, I want more awesome cannabis on the planet so I'll keep bringing it up.

 

[Bwanabud]

Common folk say anything under 200 ppm is good to go, mine is 60 ppm well water with no issues.

 

[f-e]

With water that hard (.7 EC ) that faucet filter wont do much . Your best bet would be a cheap 50GPD 5 stage RO system.

Such a high ec is likely to come from easily dissolved solids. Anything like that, is going to be in quite large chunks if you're near source. Making a 0.5 micron filter quite effective. It's something I have done a couple of times in the past.

Many water companies publish what the latest samples found. That is a good starting point, without having to get any lab work done yourself.

It's often useful stuff, without which, you have to put it back yourself. Many feeds rely on it. So ro users are often seen putting Ca and Mg in. It's not just them that feed night expect from the tap though. Other things can be lacking. Which you may not know about.


I always use tap. I have used RO but my yield was down a lot. Where problems existed, a spun plastic filter and a carbon block have sorted it. Both normal 10" jobs

 

[Nifty_PoT]

Something i forgot to mention that alot of RO growers dont know is that RO water is a poor choice to grow plants because it lacks needed mineralization namely alkalinity. you need to add alkalinity or else your ph in the medium will decrease over time causing issues. You can have the same problem with pure rainwater. You need to have about 20-25ppm residual alkalinity(measured as CaCO3) in your final feed solution, you can test this with any pool water test kit to make sure you are within range. An easy way to add alkalinity is by adding potassium carbonate before you add your nutrients to res.edit* Another thing is that you should really not flush with pure RO water, It can dissolve built up salts too quickly and basically act as a strong solvent, you end up actually burning the plant , i recommend keeping atleast 100-300 ppm in flush solution.

 

[Douglas.Curtis]

Something i forgot to mention that alot of RO growers dont know is that RO water is a poor choice to grow plants because it lacks needed mineralization namely alkalinity. you need to add alkalinity or else your ph in the medium will decrease over time causing issues.

This is an overfeeding issue, which has nothing to do with r/o. Water is a solvent, and without additional elements with it (as in tap/well water) there isn't anything to 'change/affect' pH with.

As for the general recommendation 200 ppm water is fine? My response is the truth, the general state of cannabis quality is gack nasty, so how much do you want to stick to 'general' info on cannabis?

 

[Nifty_PoT]

This is an overfeeding issue, which has nothing to do with r/o. Water is a solvent, and without additional elements with it (as in tap/well water) there isn't anything to 'change/affect' pH with.

It is not an overfeeding issue. The fact that there is no alkalinity in the water will directly affect your media ph , meaning you need something (namely alkalinity) to buffer against ph drop in the medium. too little alkalinity =ph decreases too much alkalinity and ph will rise over time.

 

[GOT_BUD?]

I would suggest getting a larger than 50gpd unit, you'll be surprised how useful it is. Everyone in my house drinks r/o including the animals, we cook with it and I find other uses where clean water is preferred over >14ppm water.

If your plan is to only use r/o the last 3-4 days, I'd skip it entirely, because it really won't matter at all. Kinda like spraying a dirty wall with a little spray bottle. That soil is caked on and won't be coming off with even a high pressure hose.

I was going to retort with, "All I need is a 50gpd for a house of two, full of plants with 6 animals."

But then I remembered I have two of them

One at the kitchen faucet for drinking and the critters, and one in the basement that waters all the plants in the house.

 

[Bwanabud]

Is it necessary to grow quality herb.....no


The clean freaks can say R/O only for pure product, but then again their pipes and rolling papers provide more impurities than quality tap/well water.

 

[TripleDraw27]

Answer - No

Unless you like wasting money on Calmag's and over thinking nutrient schedules.
Alas, most will fall for some graphic on a bottle or hearsay. GL!

 

[SuperBadGrower]

edit: Nvm, all that I said has already been written

 

[Douglas.Curtis]

It is not an overfeeding issue.

More correctly, it's an 'excess nutrients in the root zone' issue.

r/o water does not have alkalinity, it also does not have acidity, it is completely neutral. It is literally IMPOSSIBLE for r/o to change pH in any significant way except through the dilution rate. When unused nutrients are left behind they drop the pH in the media. Read my thread on using a full pH swing, it explains this process in detail.

Anyone who believes 200ppm tap water grows 'decent' quality cannabis is uneducated on quality. You literally have an epiphany coming and it's a big one. Yes, rolling papers have contaminates... so why on earth would you want to double or triple this by having contaminates in your cannabis as well?

I know what I post here won't help most of the growers here, but I'm super glad YOU are paying attention. Yeah you, the grower I'm going to be super happy to share your cannabis with some day. Thank you for paying attention, and you're welcome.

 

[f-e]

I had problems using RO water and compost. Every watering, the plants wilted like they were dry. I think it was actual osmosis, where the saline solution in the roots came back out. Perhaps rupturing cells, hence the drop. A bit of feed fixed it. So it seems to make sense. Later, in large compacted pots, it was a lot harder to notice. The RO presumably picking up salts on it's way through the older heavier medium. It was as cuttings I had real problems. Dampening rockwool blocks again, without additional feed, was loosing me cuttings. I was banging my head on the wall almost. Every watering, they dropped and I lost some. I'm surprised to of not read this story from other growers.

 

[Nifty_PoT]

More correctly, it's an 'excess nutrients in the root zone' issue.

r/o water does not have alkalinity, it also does not have acidity, it is completely neutral. It is literally IMPOSSIBLE for r/o to change pH in any significant way except through the dilution rate. When unused nutrients are left behind they drop the pH in the media. Read my thread on using a full pH swing, it explains this process in detail.

You are not understanding what i am saying lol. You are confusing alkaline with alkalinity .They are not the same thing. The buffering capacity (alkalinity) will determine how much acid you will need to ph your reservoir,after ph'ing the res the residual alkalinity that is left behind will have a big impact on the ph in your medium over time.. Here is an article that will explain it better.
https://www.greenhousegrower.com/pr...ant-nutrition-irrigation-water-alkalinity-ph/

 

[SuperBadGrower]

I dont know shit about this because I live on great water. But here's another really interesting article about alkalinity, maybe relevant to the discussion of RO

MYTH Series: Water pH Relates to Medium pH

It is extremely important to monitor the fertilization management when using water with low alkalinity (<40 ppm CaCO3) to water plants. Water with low alkalinity has a limited buffering capacity; therefore, the application of potentially acidic fertilizers can have a huge impact on the pH of the growing medium. In this case, potentially acidic fertilizers can drop growing medium pH to unacceptable levels. The same principle applies to reverse osmosis (RO) water since the alkalinity of the treated water can be extremely low.

Anyway I personally think that after more than 20 millions of years of existence the plant can handle safe-to-drink tap water. Never used RO though so who knows huh.

edit: Oops, I didn't mean to attach this image hehe. Dont know how to delete it