RO or Tap H2O

[tankdogster]

My tap water is about 6.5 where I live. I used RO water for feeding and watering on my first grow but I got to wondering. I had to use BASE to raise the PH after mixing my Nutes to get it to 6.8. I mixed a batch using the tap water and tested the PH and it was 6.5 without adding anything more. The PPM was slightly higher with the tap water but I was wondering what the growers hear thought about using RO water. I thought about mixing 1 part RO and 1 part Tap but I do not need to make things any more complex. Is it worth the trouble of using RO water at all?

 

[Growdude]

Its worth is if you have crap tap water, mine is over 800 ppm so I use RO water, rain water and dehumidifier water.

I used to use city water that I brought home in a 20 gallon drum from work but it started looking suspicious.

I let the city water sit out to evap chlorine and I suggest you do that with your tap if its city water but I never had a problem using it, but everyones water is differant, but if it reads low on the PPM's Im sure its fine.

 

[The Hemp Goddess]

The bottom line is....what is the PPM of your tap water?

 

[city]

woooo hooo. a newbie can help. Im a plumber. i have studied the crap out of water,waste,pizza, beer, and fishing....
personally i wouldnt use an RO. the only thing it lets thru is Nitrate and Nitrite, it slowly eats metal, the only thing it can be stored in is plastic, then you have the problem of plastic leaching and "offgassing". soffened water is not good either. takes away most of the undesolved solids for the plant that they live on..humans it doest matter. we get less than .01 % of our nuets from water.
water for plants. runn it thru a .05 micron carbon filter. that will remove the bads from the water such as clorine, amonia,and still leave the "total desolved solids" for the plant

 

[city]

woooo hooo. a newbie can help. Im a plumber. i have studied the crap out of water,waste,pizza, beer, and fishing....
personally i wouldnt use an RO. the only thing it lets thru is Nitrate and Nitrite, it slowly eats metal, the only thing it can be stored in is plastic, then you have the problem of plastic leaching and "offgassing". soffened water is not good either. takes away most of the undesolved solids for the plant that they live on..humans it doest matter. we get less than .01 % of our nuets from water.
water for plants. runn it thru a .05 micron carbon filter. that will remove the bads from the water such as clorine, amonia,and still leave the "total desolved solids" for the plant

 

[The Hemp Goddess]

Actually, we do not want to "leave the 'total dissolved solids' for the plant". We want to start with water free of dissolved solids and add nutes in the doses they need to achieve the PPM the plants require. This is especially true in hydroponics. Tap water with a high PPM generally has minerals and salts harmful to mj.

 

[city]

thanks for the heads up. but if this is a case of sacratic ignorance help me get tto the bottom of it.
so what we are dealing with is:
1 total desolved solids (tds)
2 total undesolved solids (tus)
3 chemicals in the water
so we know that a water softner removes most TDS except high amounts of iron.
a cloth filter removes most visable TUS and a carbon filter removes most TUS down to .05 micron,including chlorine,arsnic,lead,chromium,sodium,ammonia,cyst nitrate and nitrite.
a RO system removes all that do to its carbon filters. but the latex filter removes the rest down to the point that very minute nitrate and nitrate are about the only thing left in the water. Great we are both on the same page correct.
This may be the point that i dont agree. RO turns water acidic its negatively based(i suddenly feel stupid i forgot the term)like rain water with a negative charge).
so with that the thing that i need to understand is how can you use RO for feeding a plant when the water wants nothing more than to take the nuits away until it equals out. there has to be a base.. and if you have to add a base to that shouldnt you have just stopped at a carbon filter? get back and let me know

 

[tankdogster]

The bottom line is....what is the PPM of your tap water?

My Tap water is 490 PPM

 

[tankdogster]

thanks for the heads up. but if this is a case of sacratic ignorance help me get tto the bottom of it.
so what we are dealing with is:
1 total desolved solids (tds)
2 total undesolved solids (tus)
3 chemicals in the water
so we know that a water softner removes most TDS except high amounts of iron.
a cloth filter removes most visable TUS and a carbon filter removes most TUS down to .05 micron,including chlorine,arsnic,lead,chromium,sodium,ammonia,cyst nitrate and nitrite.
a RO system removes all that do to its carbon filters. but the latex filter removes the rest down to the point that very minute nitrate and nitrate are about the only thing left in the water. Great we are both on the same page correct.
This may be the point that i dont agree. RO turns water acidic its negatively based(i suddenly feel stupid i forgot the term)like rain water with a negative charge).
so with that the thing that i need to understand is how can you use RO for feeding a plant when the water wants nothing more than to take the nuits away until it equals out. there has to be a base.. and if you have to add a base to that shouldnt you have just stopped at a carbon filter? get back and let me know

When I use the RO water I have to add about 4 mil per gallon h2o of Mad Farmer Get up (Potassium carbonate, Potassium silicate & Potassium hydroxide) to get the PH back up to 6.8. I add the get up after the nutes.

 

[city]

so has anyone come up with anything to help me understand this any further? untill then my stance is no RO...

 

[The Hemp Goddess]

My Tap water is 490 PPM

Tap water that has a ppm of 490 should be treated. Since you probably want to run your ppm between about 500-1200 depending on the stage of growth, you have a lot of unknowns when starting with a ppm of 490 (what exactly does that 490 ppm consist of?).

When you start with water that is almost devoid of solids (both suspended and dissolved), you can add the nutes you need in the proportions you need for the stage of growth your plant is in--no unknowns. Since you want your ph on the negative side of 7, any acidity of the water is a plus--most people have to use ph down to get their ph in line with what it should be.

Softeners use salt (sodium) and softened water should be avoided for plants. Carbon filters will not remove dissolved solids. An RO is the easiest, cheapest way to insure that you are starting with "good" water.

 

[HMAN]

Comparing Carbon Block, Reverse Osmosis and Other Common Water Filtration Methods

Comparison Chart

The general public is justifiably confused about differences among water filtration approaches and their relative efficacy. When one begins shopping for a water filtration device, he is immediately presented with a rather bewildering set of choices and the daunting task of choosing from among reverse osmosis, KDF, carbon block and even distillation – to name the most common. In the following article, we have endeavored to describe each of these approaches in limited detail and then compare and contrast these various types of filtration technologies to assist you in making an informed decision when it comes time to purchase a water filter system.

Carbon Block Technology

With carbon block filters, water is forced through the pores of the densely compacted carbon block, where a combination of mechanical filtration, electrokinetic adsorption, and physical/ chemical adsorption take place to reduce a wide range of contaminants. Solid Carbon Block technology can reduce chlorine, taste and odor problems, particulate matter, and a wide range of contaminants of health concern -- cysts (cryptosporidium and giardia), VOCs (pesticides, herbicides, and chemicals), certain endocrine disrupters, Trihalomethanes (cancer-causing disinfection by-products), heavy metals (lead, mercury), turbidity, MTBE, Chloramines and asbestos. Solid carbon block filters do not remove healthful, naturally-occurring minerals, require no electricity, and do not add salt or silver to the water
Reverse Osmosis

Reverse osmosis (RO) has been known for more than a century, but it did not become a commercial process until the early sixties when a special membrane was developed (1,2,3,4). Because RO operates at a comparatively low temperature and is relatively energy efficient, it is employed in various applications, e.g., desalination, treatment of waste water, reclamation of minerals, concentration of whey and other food products, and purification of water. While RO will remove certain contaminants and additives that carbon block filters will not (i.e fluoride and nitrates for example), it has a number of downsides as well. These include: RO has no independent ability to reduce most Volatile Organic Chemicals (VOC's); it has very low output - takes up to 24 hours to process 5 gallons of water; you must have a holding tank to store the processed water; considerable water is wasted - for every gallon processed, 3 to 9 gallons are wasted and it removes minerals and trace elements essential to good health.

In the RO process, feed water is passed through a prefilter after pH adjustment, and is pumped to the membrane modules at the designed pressure. The product water is then pumped to a storage tank and the concentrate is drained (6). Most RO units with a cellulose acetate membrane are designed to operate between 55 F - 86 F. (13 C - 30 C). In practice, the feed water may go through any one or a combination of several of the following pretreatments: sand bed, chlorinator and retention tank, anthracite filter, activated charcoal filter, degasifier, microfilter, neutralizer, and deionizer, depending on the condition of the feed water and the desired quality of the product water. Since water conditions may vary from time to time, adequate pretreatment must be provided so that the dissolved solids and the bacterial level of the feed water, after prefiltration, can be controlled within the designed limits. In othere words, to get adequate treatment and a resulting safe water product, RO must be combined with othere technologies such as carbon block and/or granulated activated carbon.

Charcoal Filters or Granulated Activated Carbon (GAC)

These come in powdered or granulated form which allows water to flow around rather than through the carbon.Referred to as taste and odor filters because of the limited contact time the water has with the carbon.

KDF

In the KDF application, water passes through a bed of a media made of a special high-purity alloy blend of two dissimilar metals - copper and zinc KDF-55D. This media, patented in 1987 by KDF Fluid Treatment, Inc., is a major advancement in water treatment technology that works on the electro-chemical and spontaneous-oxidation-reduction (redox) principles. Chlorine is instantaneously and almost inexhaustibly oxidized.

Silver-Charcoal Filters

Same as Charcoal Filters above; however, uses silver to inhibit the growth of bacteria while water sits in filter.
Silver ingested in certain doses can be poisonous to the human body; therefore, it must be registered with the EPA as containing a poisonous substance.

Limited Media Filters

As the demand for quality drinking water continues to grow, new types of media will be test-marketed, from metal shavings to coconut shells. Some materials can be quite ”exceptional” in reducing a particular contaminant in the water, but there is a wide range of contaminants that should be addressed - not one or two.

 

[puffnstuff]

city, you are 100% spot on, I have been in the water treatment and filtration industry since 1996. There are of course different water chemistries in everyones diffrent location, and in some cases ro would be better than their existing tap,well or river water. But I have always wonder why some people want to take all of the good stuff out of their water? guess it's because it's what they have been told to do.
puff

 

[city]

i dont think its takeing so much good stuff out of the water for human consumption. we get less that 1% of our nuets from water. i have to read up on plant intake

 

[The Hemp Goddess]

city, you are 100% spot on, I have been in the water treatment and filtration industry since 1996. There are of course different water chemistries in everyones diffrent location, and in some cases ro would be better than their existing tap,well or river water. But I have always wonder why some people want to take all of the good stuff out of their water? guess it's because it's what they have been told to do.
puff

I'm sorry, but I have to continue to disagree. The thing is that we do not know what is in the water--we do not know that it is good--we do not know what salts, minerals, etc are making up the ppm of our water. Many of the things in tap water are not good for mj. We are NOT taking out GOOD things--we are taking out unknowns and we are adding the nutrients that we KNOW that mj needs to flourish. When we are talking about RO water here, we are specifically talking about using it for the growing of mj, nothing else. IMHO, there is no debate about the benefits of using RO water for your mj if your tap water has any significant solids, dissolved or suspended.

 

[city]

sorry couldnt think of a clear title.
I completely see what your talking about when you want to start from scratch using RO.
But my point of view with RO is the negative charce that it has from going thru the latex filter. wouldnt distilled have the same quality without the negative charge?
I believe that starting from scratch on water and adding in would be great. I think a great test to see would be to get some RO and carbon filtered distilled water. and see if there is any nuet difference with a conductivity meter. (I cant afford one of these so someone will have to let me know).

 

[bombbudpuffa]

I use tap water. My grows are much better with it but like a few said before..it depends on the ppm.

 

[CasualGrower]

Tap water is different depending where you live..... Some water will come out of limestone or sand stone aquafers... Some out of rivers and lakes and some out of Ground water that can contain Sulfur. Some water is better than others.

The level of the PPM's in the water is not what is in question. The big question is, What is in the water, not necessarily , how Much.

For Example, My tap water runs about 200 PPMs give or take 25. But I also know that my water comes from the aquafer underground and has a bit of Lime (Good) and some other Trace elements that are good. Now in the treatment process you get Flouride ( Not sure if that is good or not for MJ) and some Chlorine... ( Not good for MJ but I use a DWC with a nice rolling bubbly bath which will remove the CH from the water pretty quickly. So I do not worry about it. Could also add a few drops od Dechlor, an aquarium additive for fish and plants, but as I said I dont worry about it.)

Might get some other stuff in trace amounts also....

If I am thinking correctly, I think that all Municipal water districts are required to have an up to date Water Purity Analysis available at their office for inspection by the public.... this analysis will tell you everything that is in your water and the amounts that is there. Or you can have your tap water tested independently.



I was gonna do a lil experiment on my next grow with half my plants in RO water and half in Tap, but decided against it since my water is actually pretty darn good.... Would be interesting to see this done with someone that has marginal or nasty tap water though.

 

[The Hemp Goddess]

The ph of the water will not always be lowered. Here is a good link explaining how, why, and when the ph of water is lowered by going through reverse osmosis:

hwwp://www.freedrinkingwater.com/water-education2/ro-ph.htm

Also, could you explain carbon filtered distilled water? I was under the impression that distilled water was virtually pure and would need no further filtering.

 

[puffnstuff]

Miss godess you are welcome to disagree all you want. I am not trying to sell you on any ideas here. I said sometimes ro is better. But you ARE taking good stuff out of the water with ro. the primary water "contaminates" are calcium, magnesium, iron, sulfer and manganese. All of these are good for us and mj in small quantities, am I wrong? Granted there are litteraly thousands of other things that COULD be in YOUR water. Some area's have known problems and you should check your water source to see if there is anything to worry about. But to use ro just cuzz....well thats what I'm talking about. A lot of people believe that their water just HAS to be bad, thats what they read, hear and repeat to everyone they know. It seems to run in certain circles too. When I pull up at a customers house and see a volvo, bmw or electric car I automaticaly know they will be wanting ro. It may be stereotyping but I am 90% + on ro sales to volvo owners, go figure. And taste? you ever taste your ro water WITHOUT the carbon filter installed? yuck. Best tasteing water is ozone, next would be water thru carbon. The taste of water comes from what is in it. mother nature did a pretty good job in some places, really screwed it up in others. Dont even get me started on chlorine and the myth's I read.
puff