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Filters for chloramine/chlorine

To use filters for removing the antibacterial (anti-cholera) agents
introduced by your water service, first get a chlorine test kit. [You can
pay a lot for one at the local fish store (LFS) or get a much larger one for
way less money in the pool dept. at Home Depot o/e. They both use the same
chemicals and color charts.]

Chlorine and chloramine both give positive readings on a normal
color-changing chlorine test. You want a reading of zero, none, or less than
that if possible. <G> *Any* detectable amount should be considered
gill-damaging, even if it does not make the fish gasp at the surface or swim
inverted. That's why I don't do partial water changes right from the tap,

Reverse Osmosis (RO) filters remove lots of things, but chlorine, chloramine
and ammonia apparently are not among them. Even the cheapest RO units have
extra sediment and activated-carbon filters to get stuff that either would
damage or get through the membrane. In addition, they all have flow
restricters to assure good long contact in the filters or membrane for
efficient removal of unwanted stuff.

RO water is *too* pure for 99.9% of fishkeeping, so a good practice is to
mix hard tap water with dead-soft RO water to get an ideal mix for your kind
of fish. Fortunately, most of us living in North America are sitting over
ancient sea beds. The shells (limestone) in the aquifer make our water good
and hard. Trace minerals needed by fish and plants are also abundant in the
water. [I feel sorry for the poor folks who have water so soft they are
continuously making "chemical soup" to overcome the plant-stunting and
stability problems caused by that lack of the essential minerals.]

The tap water can be slowly trickled through an ordinary big, whole-house
filter (roughly 3"D x10"L ) with an activated-carbon cartridge to remove
chlorine or chloramine. Frequent testing of the output is needed, for the
carbon eventually saturates, allowing chlorine to "punch through." On advice
from my local water engineer (who happens to be trained as a marine
biologist), I use two filters in series, with a tap between. The second
filter catches any "punch through" between tests. I replace it with a new
cartridge if I detect chlorine at the tap between them, and put the replaced
one in place of the worn-out #1 cartridge, for it is essentially still new.

I also have a valve in the incoming line to restrict flow into my storage
barrel (trash container) to a trickle. The swamp-cooler float valve I have
installed near the top also helps by allowing only pretty slow flow, but
keeps the carpet much drier than before. (^_^)

The real key to making filters work is to frequently test the output, until
you know their capacity. Then you can cut back. Weekly tests make no sense
for me, since my tap filter goes for considerably more than 6 months before
needing a change. I use as little RO as possible, so the *three* carbon
filters on it are essentially good for life -- well for a few years, anyway.

As a final precaution, I add some "Amquel" to my storage barrels, to handle
any ammonia that might still trickle through as the chloramine breaks down
in the filters. I have a huge number of baby fish, and I don't want ammonia
to get above a few parts per billion. As I can't possibly test for that, the
"Amquel" assures me that growth will not be inhibited by low-level
ammonia/ammonium that I otherwise could miss.

I'll finish as I started, by saying you must test, test, test. Filters work
fine, if you do. Different brands have different effectiveness (as we have
heard here, recently) and the expensive ones are often also the poorest.
Test to know.


PS. Did I mention that you should check your filter output for chlorine? ;-)

PPS. As a matter of standard practice, I use pure tap water whenever
possible, to avoid accidents with osmotic-shock problems. RO is used very
stingily, and only if vital. I therefore can't grow *Glossostigma* worth
diddly. :-)
Wright Huntley, Fremont CA, USA, 510 494-8679  huntleyone at home dot com

         "DEMOCRACY" is two wolves and a lamb voting on lunch.
     "LIBERTY" is a well-armed lamb denying enforcement of the vote.
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