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Re: Do we need RO filters (long)


Sorry I'm a bit late to this thread.  If you are processing water using
Sodium Thiosulfate (the main ingredient for commercial dechlorination
chemical treatments) or by RO filters, the problem with these methods are
that they don't completely remove the chloramine, they remove the Chlorine
but the ammonia/um (sp?) still passes through.  The next step you must take
is to use zeolite ammonia removing media.  You must use 1 gram of zeolite
to remove 1.5 mg ammonia in 10 gallons of water (using a minimum of 25
grams, I read this in a book somewhere but I forgot where).

I've found one of the best companies for water filtration (for both
aquariums & drinking water) is SpectraPure www.spectrapure.com.  Talk to
one of the Charles (one is the owner & the other is a tech support guy).
Both have vast knowledge about water filtration.  They do have a
rechargable cartridge specifically for chloramine.  Here is an explaination
of the product for thier RO units from there website:
Chloramine Removal Cartridges for RO
- For post Reverse Osmosis use
- Removes heavy metals, including lead, copper and zinc
- Use on water supplies treated with chloramines
- Regenerable with salt water 

SpectraPure® Chloramine Removal Cartridges are designed for post Reverse
Osmosis removal of chloramines. Use of a RO System alone will not remove
the ammonia component of chloramine from tap water supplies. Our ammonia
removal cartridges have been especially optimized for post RO removal of
ammonia and will reduce it down to undetectable levels. These cartridges
can be easily regenerated with salt and reused many times.

I personally don't use an RO unit (and I don't have chloramine treated
water) but I do use TWP DI Resins and recharge them when they are exhausted
(about 300 gallons for my very soft water, I need very pure water for my
coral reef tanks).  I like the DI resins because they waist little water
(about 5 gallons when you recharge them) and they provide very pure water
(around 0.18 ms).

For the instructions on how to recharge the resins try this site:


This is the website of the guy who invented the procedure.

If you have a RO unit, try this method I found on the Usenet to increase
your production while decreasing water waste:
Most RO unit ratings are based on the following baseline data:

500 ppm Total Dissolved Solids in the water
ie.  The more solids in the water the higher the pure/waste water ratio is.

77F source water tempurature
ie. the high the tempurature the more productive the RO membrane is.

60psi water pressure.
ie. The higher the water pressure....... the more water can be produced.

Three factors effect the production of RO water:

1.  Total Organic & Inorganic material in the source water.
You can't really change this (thats why you are using an RO unit)

2.  Source Water Pressure
You can buy pressure pumps (I think that Kent makes one) to increase the
water pressure.  Most water pressure (at least in major citys) is 60 PSI.
The minimum PSI to operate an RO unit is 45 PSI.

3.  Source Water Tempurature.
The e-mail below is an idea that I got from one of my reef keeping lists.
It has inceased the production of my RO water by quite a bit.

> Hi,
> My  ro unit is not producing the rated gpd that is specified.  I know that
> the production rate is depended on three things: 1. water temp. 2. water
> pressure and 3. solids in the water.  The water pressure is strong (65 psi)
> and the solids are actually very low (150 ppm), so the only thing that
> could be causing my lower production rate is the low water tempurature of
> the feed water (around 45 degrees).  I recieved this idea from one of my
> reef lists to increase the water production of my ro unit (CSP/DI 50 GPD):
> 'I came across a neat strategy for increasing the output of RO units, and I
> thought I'd pass it on. Tell me if you've heard this one before. Take a 5
> gallon bucket, fill it with warm water (or toss in a heater), and run about
> 50 feet of high pressure turbing from the spigot to the RO unit - coil the
> 50 ft. length into the bucket of warm water. Voila - a heat exchanger.
> Around here where the water is about 45 degrees at 80 psi, this trick
> tripled my output...'
> I was just wondering if the quality of the water produced would decrease
> with the increase in water tempurature.  Any information that you could
> give me would be appreciated.  Thanks.

[answer from SpectraPure]
>>Thanks for sharing the idea. We have heard of several similar solutions,
>>including ( After doing what you have done) returning the waste water to the
>>container to capture more of the BTU's.
>>The Purity will drop ever so slightly, less than 1%

As per usual, I have no affiliation with any company mentioned in this e-mail

I hope this helps.  Good Luck.

Victor Eng				Vancouver, BC, Canada
engfam at axion_net