Can I use an R.O. system?

[iceolated]

Our water quality in town is starting to drive me insane. High pH, high TDS, high hardness.

I have two items in mind...Aquarium Pharmaceuticals Tap Water Purifier or an R.O. system.

Here are the average paramaters for our city's water (full details found at this page).

Hardness 102 mg/l or 5.9 grains per gallon
Total dissolved Solids 733 mg/l
Conductivity 1220 umhos/cm
Sodium 223 mg/l
Fluoride 1.24 mg/l
pH 9.3
Calcium 53 mg/l
Iron 0.0833 mg/l


Will an R.O. unit work with that amount ot T.D.S.? Also, most R.O. units seem to require water between 50-70F. Not a problem in summer, but when it's winter here (-30sF) the cold water line is barely above 40F Does the water going into an R.O. unit have to be a mix of warm and cold?

Also, I am slighlty ignorant on what I need in an R.O. unit. Can someone point me to a link with more info. I see that some have one or two carbon filters, micron filters and then a de-ionizing filter.

The Aquarim-Pharm says it deionizes water and is significantly cheaper but I know that cartridge life will be many times shorter.

Here's what I want in water:

Neutral pH
No hardness modifiers, (Calcium, Carbonate or Bicarbonate)
Good particulate removal

What's my best option?

Thanks,

Gary

 

[annka5]

I think to get he water you want then RO water is absolutely your only option.
Am not clear if you have a unit yet or not - either way, i would get in touch with manufacturers / look at manufacturers web-sites to choose best unit for your needs / figure out how to use yours as they are relatively expensive to buy.

 

[Lateral Line]

RO is the only way you'll get near what you want from that starting stock, which actually looks horrible. Your tap water stats look more like toxic waste figures then drinking water!

I'll warn you though. A simple, (therefore cheap), RO will not clean that mess up. Yes, the water will be a lot better with a lower pH, hardness and TDS, but you'll be nowhere near what you want.

I've never seen temperature limits before, but it makes some kind of sense. If the water is so cold that ice crystals could form, the membrane will be damaged, same is true if the water is to hot for the delicate plastics. I guess the pore size may also be affected by thermal expansion/contraction at temperature extremes.

I assume you are aware that the water you are aiming for is not really suitable for tanks. Being unbuffered it can and will swing wildly in pH. Unless you really understand your water chemistry, you'll need good buffering, (hardness of 3 or more).

True, blackwater, zero hardness tanks are very high maintenance and require constant monitoring. I would not attempt such a rig in less then 100 gallons.

 

[kamel_007]

man,,

RO system is nessecary...

ur tap water values is to strang to ur fishs

 

[iceolated]

Thank you all for the replies.

Yes, I'm aware that unbuffered water such as in my requirements won't work for an aquarium. My plan was to get water as pure as possible to which I could then add controled amounts of the necessary minerals and electrolytes using something such as eletro-right.

I'm thinking that the better the water I start with the easier it is to maintain good water quality.

I try very hard to avoid chemically adjusting my tank water any more than absolutely necessary. Less is more so to speak.

I'ved got a few years background in water quality, an old career involved my sampling and testing water for many parameters but we never dealt with RO units. With than in mind, I know how widly our water parameters can swing and I'd simply like to reduce the amount of variables.

Next year will see the completion of a water supply project that will start to supply our town with Missouri river water in addition to our current source. I think it's time I take control of the water coming into the house.

Regards,

Gary

 

[jimboliana]

iceolated, yes you need a RO unit get the best you can afford, prices have come down in the last couple of years

dont worry about how cold the water is, the RO can handle from 5-35 degrees C as for what you need, get a carbon pre-filter which takes out the chlorine and other heavy metal and containments removal

The RO membrain itself and with water per. like yours get a small DI unit which will bring down the TDS a bit more, a DI unit will polish the water for you

Hope this helps

 

[Ed4567]

The efficiency of the ro membrane is affected by temperature- the higher the temprature the greater the efficiency. I'm not sure why this is, although my feeling is the increased k.e. of water at higher temperatures makes it 'easier' for pure water to move across the membrane.

Maybe best to check with a manufacturer before buying?

 

[iceolated]

Hi guys,

Hate to drag this subject up again, but I am thinking of restarting my 46 gal bow front tank (shut down about 4 months ago when my oscar Hemmingway died).

Back to the RO unit thing. Most of the manufactuer's recommend water in the 74-82 F range for the input line. Who on earth has water like that? Assuming that one has to use warm or luke warm water, how do other RO users go about regulating that. Whether one has a two tap or single tap faucet how do you regulate the temp of the input water?

Thanks for any and all input.

Gary

 

[karlp]

Hi Gary

The manufacturers all rate their units at certain parameters. The units are less efficient at lower temperatures and less efficient with higher dissolved solids, but still work fine. They do this, because at lower temperatures and higher dissolved solids, the unit will not meet their rated gallons per day and you may get different rejected solids figures.

In my area we have hard water significantly higher than the rated figure and at the moment colder than the rated figure, so the gallons per day is less than their rating.

All I've done is buy an RO unit bigger than I need and it's fine.

Make sure you get one with a flush facility to help extend the life of your membrance because you'll need it with that water.

Obviously if it's allowed to freeze it could be damaged.

It is possible to add a resin unit as well to clean up any remaining solids.