scientific and residential fish owners have tanks and ponds that
range from one gallon to several thousand gallons, and there is
no "magic formula" for . We can give you some general
ideas of what works or what others have done to neutralize chloramine:
Activated charcoal (carbon) filtration systems
Sodium thiosulfate (dechlorinates but doesn’t deal with
Commercially available dechloramination products (check the labels,
since some simply remove the chlorine, while others "lock
up" or detoxify the remaining ammonia)
Catalytic ( GAC) carbon
A chemical agent plus a biological filter (agent to remove chlorine,
biofilter to remove the ammonia)
It is important to test your pond water to make sure there is
not a build-up of ammonia.
FACTS AND ANSWERS
Unlike chlorine, chloramine will not dissipate to the atmosphere
by standing or aerating.
Boiling will not remove chloramine.
Chloramine passes through the gills of fish and directly enters
In the blood, chloramine chemically binds to the iron in the hemoglobin
in red blood cells causing a reduction in the cells capacity to
Chemical additives for dechloraminating water you add to your
tank or pond (makeup water) are available at pet/fish supply stores.
Sodium thiosulfate added to chloraminated water will neutralize
chlorine, but ammonia is released.
Water should ideally be dechloraminated in a separate container
to neutralize chlorine and ammonia before being added to a tank
A pond with an established biological filter (one that has cycled
through the nitrogen cycle – has converted ammonia to nitrite
to nitrate) can remove ammonia.
Tap water used with artificial sea salts for makeup water in salt
water fish tanks must be dechloraminated.
The proper amount of neutralizing chemical is sometimes added
to the pond prior to or simultaneously with the makeup water.
Water additions should be as small as possible, so the fish are
not stressed as the biological filter cleanses the water. Avoid
large water changes.
Adjustment of pH may be more critical because of the possible
addition of ammonia. At a pH of 8.5, ammonia is about 11% un-ionized,
which is the potentially toxic form but at a pH of 7.0 it is only
The quantity of makeup water to be added should be estimated to
determine the required amount of dechloraminating chemical. The
water quantity can be found using the water meter, timing the
filling of a bucket, or by the amount the pond depth would increase,
not the total pond volume. (Depth increase: multiply length times
width times depth – all measurements in feet – to
obtain the volume in cubic feet, multiply that by 7.5 to obtain
the gallons of water to be added.)
Automatic makeup water systems may have to be operated manually
to allow the proper amount of dechloraminating chemicals to be
added simultaneously with the makeup water.
Carbon filters should be operated at a slow rate for best chloramine
removal. They should be monitored carefully to determine when
the carbon media has reached the end of its useful life and needs
to be changed. Manufacturers often indicate the maximum number
of gallons that can be filtered before renewal of the filters
is required. Check with the supplier for proper operation. Testing
the residual from the filter will help determine the best filtration
Runoff from lawns or gardens should not be allowed to enter a
pond because of the possible presence of chloramines, fertilizers,
insecticides, pesticides, and/or any other material that might
contaminate the pond.