Tap water VS. RO pro's and con's

  • Thread starter Randyb
  • Start date
  • Tagged users None
R

Randyb

68
0
If you let municipal tap water site aerating a few days in barrels is there any real difference than using RO water for growing? We have some of the best tap water in the country and funds are zip for buying a decent RO system. Any thoughts.
 
H

Hythloth

46
6
If you let municipal tap water site aerating a few days in barrels is there any real difference than using RO water for growing? We have some of the best tap water in the country and funds are zip for buying a decent RO system. Any thoughts.

It really depends on the quality of the tap water in your area. Some people already have less than 100ppm from their tap which is decent. In my area, the base ppm for my tap water was already 470ppm which was just ridiculous, so I pretty much had to use RO water, otherwise the plants would suffer.

Also keep in mind that bubbling your tap water definitely does not get rid of all the chemicals that the city puts into your water. RO water just gives you a very nice base to start from, so you know exactly what's in your water.

You say you have some of the best tap water in the country so maybe you'd be fine without RO, but definitely check it with a good EC/PPM meter first.
 
R

RMCG

2,050
48
What are you trying to do?

If 'aerating' is to remove chlorine, that will work. If you are trying to remove Chloramine (some cities use this instead), that will not work.

Chloramine (derivative) is a key ingredient in DM Zone.

If you want to remove chloramine, Prime or AmQuell (from the fish store) will break the chloramine bond (ammonia and chlorine).

Most use RO to get as near 0ppm water as possible by removing the ~other~ things that are in the water, not just chlorine/chloramine. Check your local water supply website for analysis to see whats in there.

My tap is ~170ppm. I run it through a whole house filter (Not RO) and it gets down to ~110-120ppm. Good enough for me...
 
H

harley34

101
0
Really?

I find that hard to believe. I would recheck my meter.

yeah no joke, thats what i thought! Using 2 blu lab truncheons aswell, to cross check each reading. Calibrated and cleaned often etc. my ph is dead on 7 aswell.

So im guessing its not common
 

Buddy Flowers

Guest
i found a baby in my tap water back in philly. was gonna call child protective services but my girls needed some cal mag so i just mixed the baby there for nutes


you guys have a great day
 
UCMENOW

UCMENOW

1,095
83
RO's alot more than a dechlor unit.

If you've got good water don't sweat the RO......if your TDS exceeds 250 RO is very helpful to get the source water brought back to a more suitable start for adding nutes to. Remember, starting with TDS rich water is like painting a picture on a smeared canvas, the cleaner the canvas the better for optimizing mineral availability.

Different nutes react better with tap and some a blended for RO (0-30 ppm) water......research what is recommended for the nute you choose and go from there.
 
woodsmaneh

woodsmaneh

1,724
263
chloramine can be emanated from city water by using a charcoal/activated carbon filter.

I put this here as some people just don't want to read a long post, it is food for thought.


Research studies have reported that chloramines in hydroponic nutrient solutions can cause growth inhibition and root browning in susceptible plants. One study reported that the critical chloramines amount at which lettuce plant growth was significantly inhibited was 0.18 mg Cl/g root fresh weight, however, the levels at which some other species would be damaged is as yet undetermined. Similar problems exist with the use of other water treatment chemicals; chlorine and hydrogen peroxide are good disinfection agents, but too much in the hydroponic nutrient will cause root damage and just what is a safe level is dependant on a number factors such as the level of organic loading in the system.

Many indoor gardeners are reliant on municipal water supplies and have few other options for a better quality water source. It’s likely that some plant losses have and do occur as a result of some municipal water supplies, particularly in sensitive species and in water culture systems where there is no media to act as a buffer. On the other hand, many municipal water supplies are quite suitable and given that they have had organic matter and pathogens removed already, are a good deal as far as hydroponic systems go. Interestingly plants have rather different responses and requirements from a water supply than humans and this is where problems can occur. Municipal water treatment ensures that drinking water meets the World Health Organization (WHO) and EPA standards for mineral, chemical and biological contamination levels, making it generally very safe to drink and use. However, what is safe for us to drink may not be so good for plant growth, particularly when we consider many hydroponic systems are recirculating which allows build up of unwanted contaminants in the plant root zone.

Recirculating solution culture systems such as NFT have less buffering capacity to water treatment chemical residues than organic media-based systems.


Water treatment options used by municipal suppliers change over time and hydroponic growers should be aware of the implications of these. Many years ago the main concern was the use of chlorine as a disinfection agent to destroy bacteria and human pathogens. Chlorine had the advantage in that it disinfected water effectively; however, residual chlorine in water sources, which could often be detected by smell, could be toxic to sensitive plants and where it built up in certain hydroponics systems. Also when chlorine reacts with organic matter it forms substances (trihalomethanes) which are linked to increased risk of cancer and other health problems. Chlorine was, however, quite easy to remove from water with the use of aeration or even just aging the water a few days before irrigating plants. In the 1990’s it was found that some organisms such as Cryptosporidium were resistant to chlorine and the resulting health issues from this meant that drinking water regulations were changed and alternative disinfection methods began to be used. These included use of ozone and UV light, chloramines (chlorine plus ammonia) and chlorine dioxide.

Filtration, flocculation, settling, UV and ozone used for water supply treatment are non problematic as far as hydroponic systems go, as they leave no residue and are effective. However, use of chloramines and some of the other chemicals by municipal water treatment plants may still pose problems where high levels are regularly dosed into water supplies. Chloramines are much more persistent than chlorine and take a lot longer to dissipate from treated water, so gardeners who are concerned can use a couple of different treatment methods just as those with aquarium fish often choose to do. There are specifically designed activated carbon filters which can remove most of the chloramines in a domestic water supply and also ‘dechloraminating’ chemical or water conditioners available in pet shops. Carbon filters must be of the correct type that have a high quality granular activated carbon and allow a longer contact time which is required for chloramines removal. Even then not every trace may be removed, but levels are lowered enough to prevent problems. Use of ascorbic acid (vitamin C) is also used in the industry, and by laboratories to remove chloramines from water after they have done their disinfection job.
Chemicals are also added to drinking water to adjust its hardness or softness, pH and alkalinity. Water that is naturally acidic is corrosive to pipes and sodium hydroxide may be added to reduce this. Sodium is a contaminate we don’t need in hydroponic systems, but may be present at surprisingly high levels in certain water supplies. Domestic water softeners may also contaminate the water with sodium which is not seen as a problem for drinking, but can run amuck with a well balanced hydroponic system and sodium sensitive crop.

What water problems may look like

It’s extremely difficult to determine if something in the water supply is causing plant growth problems. Root rot pathogens may originate in water, but they can come from a number of sources, including fungal spores, blown in dust or brought in by insects. Mineral problems can be a little easier to trace if the water supply analysis is available to check levels of elements. Plant problems which may be caused by water treatment chemicals are difficult to diagnose as some plants are much more sensitive than others and the type of system also plays a role. Research studies have reported that chloramines in hydroponic nutrient solutions can cause growth inhibition and root browning in susceptible plants. One study reported that the critical chloramines amount at which lettuce plant growth was significantly inhibited was 0.18 mg Cl/g root fresh weight, however, the levels at which some other species would be damaged is as yet undetermined. Similar problems exist with the use of other water treatment chemicals; chlorine and hydrogen peroxide are good disinfection agents, but too much in the hydroponic nutrient will cause root damage and just what is a safe level is dependant on a number factors such as the level of organic loading in the system.

Hard water

Hard water is water that has a high mineral content, usually calcium and magnesium, with calcium present as calcium carbonate or calcium sulfate. Hard water can occur in wells and municipal sources and has a tendency to form hard lime scale on surfaces and equipment. A hard water supply is generally not a major problem for hydroponic gardens; calcium and magnesium are useful elements for plant uptake, however, high levels in the water can upset the balance of a nutrient solution making other ions less available. Commercial growers routinely use hard water supplies and adjust their nutrient formulation to take into account the Ca and Mg naturally occurring in the water and also adjust for any alkalinity problems with water acidification. Smaller growers can use one of the many excellent ‘hard water’ nutrient products on the market to get a similar effect.

Ground water – wells

Many commercial hydroponics growers use well water for hydroponic systems and adjust their nutrient formulations to suit the natural mineral content of their water supply. Smaller growers would be advised to find out what is in their well water source just to check for potential problems as water which has percolated through soils tends to pick up some minerals and in some areas, high levels of unwanted elements such as sodium or trace elements. Well water can also contain pathogens and may need treatment before use, although often it is just the mineral levels that need adjustment. Water from dams, lakes and springs is usually similar to well water, but can contain much higher levels of sediment, organic matter and fungal pathogen spores.

Rain water

Rain water collection can be a good way to bypass problems with municipal or well water in some areas; however, there are still some risks. Acid rain from industrial areas, sodium in coastal sites and high pathogen spore loads in agricultural areas can still occur. Generally rain water is low in minerals, but in the process of collection from roofs and other surfaces, can collect wind blown dust and fungal spores. While this is generally not a problem for healthy plants, rain water should be treated before use with young seedlings and clones where pathogens could infect sensitive tissue and open wounds.

Solutions to water quality problems

Organic material such as coconut fiber gives a greater buffering capacity for some water problems, including residues from chemical water treatments, than solution culture systems. Drain to waste media systems are also useful where the water supply contains unwanted elements such as sodium as these aren’t as susceptible to the accumulation that can occur where the solution is recirculated over a long period of time. Where problems with unwanted minerals and very hard water exist, frequent changing and replacement of the nutrient in the system can also be useful to keep things in balance. Water with a high alkalinity will need considerably more acid to keep the pH down to acceptable levels than water with low alkalinity; however, by acidifying the water first before making up a nutrient solution or adding to the reservoir, much less acid will need to be added to the system to adjust pH over time.
There are a range of other treatment options that indoor gardeners can use to improve the quality of their water supply. If pathogen contamination is an issue, slow sand filtration is one of the most effective methods, although perhaps not that practical for those with limited space. Chemical disinfection methods for pathogen control include hydrogen peroxide, chlorine and other compounds, although care should be taken that most of the active chemical has dissipated before the water is used to make up the nutrient solution. Heat, distillation, reverse osmosis and UV treatment can all be used for pathogen control, with many small RO and UV treatment systems now on the market. UV filters for aquariums can be used for small hydroponic growers to treat water with good success, provided sufficient contact time is allowed. If excess minerals or unwanted elements such as sodium are present in a water supply, reverse osmosis (RO) or distillation can be used to remove these. Organic matter in ground water sources can be removed with settling and filtration and treatment with H2O2, while chemical contamination problems and removal of water treatment compounds are more easily treated with the correct type of activated carbon filter with a sufficient contact time.

Super-charged water for hydroponics

While it seems logical that pure, clean and demineralized water is the best place to start when making up a hydroponic nutrition solution, the possibility of creating a water source that has certain benefits for plants is a relatively new concept. Water is not just a carrier for essential nutrient ions, the nutrient solution becomes a whole biological system in its own right with organic matter, root exudates, various species of microbes including fungi, bacteria and their by-products (both good and bad), beneficial and unwanted mineral elements and a range of ‘additives’ growers may be using. Some studies have found that inexplicable growth increases could be obtained using certain ground water sources compared to rain or RO (essentially pure) water to make up a hydroponic nutrient solution indicating there may be natural factors in such waters which have benefits. Not all ground water sources have this effect; in fact, some can have negative influences on plant growth. Furthermore, another essential plant nutrient – oxygen in dissolved form - is usually present in water supplies; however, some water treatment processes can drive much of the dissolved oxygen (DO) out of a water source. In theory it would be possible to not only remove those things in the water we don’t want – pathogen spores, unwanted minerals, chemical residues from water treatment - but to also ‘boost’ the water with useful properties such as a high DO content, a population of useful and disease suppressant microbes and some natural and potentially beneficial minerals and compounds. One way of achieving this would be with the use of slow sand filters or mineral filters for water supplies which are inoculated with beneficial microbes and with oxygenation of the water for a few days before making up nutrient solutions or topping up reservoirs. Further down the track we may see quicker and easier methods of ‘supercharging’ water for hydroponic systems, taking water quality to a whole new level of science.
 
R

Randyb

68
0
Lots of good info here, Many thanks.

I have often tested my water over the years and found it to be consistently under 100PPM but the PH fluctuates between 7.5 in the colder months to 9.3 in the summer time. I think the PH is regulated to preserve the pipes the water travels through.

A few years back I was told that there is old wooden pipes still flowing water close or under the city of Providence, basically hollowed out tree's. This person once worked at the DOH in the in the water dept for testing. It's been a while sense we've talked.

Thanks all for the input.
 
Calixylon

Calixylon

815
143
I use to use my tap, i live on a well now that has good water, but as long as your tap dosent have chloramine, whihc cant be bubbed or evaporated out easily like reg chlorine. Go online and check your town water report, there will be info online.
 
Irishmartin

Irishmartin

34
8
What is ro I'm from UK I use tap water ph at 5.8 when I feed my babys
 
Top Bottom