Try Salt First
Reasons for Salt
Salt. I Think Not
Reasons to Salt
The Koi Wonder Drug?
(and How To Measure How Much You Have)
Pond Care makes an inexpensive test kit no.163. It is easy to use and I
have found it at Petsmart. Year round salt in your pond may not be
needed and may result in salt resistant parasites. Some new fish may
have salt resistant disease or parasites. Salting twice a year for two
weeks at up to 0.3% can be used as a prevention. Salt alone may not kill
some parasites. If your fish are sick proper identification by use of a
Microscope will verify treatment. Most parasites can be seen at low 50x
magnifications. Inexpensive scopes work quite well. Quarantine and
inspect new fish. Some live foods may also introduce disease. Prevention
is the best cure. Here is an other formula for pond volume. Buy a salt meter, a 40 lb bag of salt and an accurate scale.
#Salt X 12 / (R2-R1)% salinity= Volume of water in Gallons
i.e. Pond reads 0.02%. 15 lb of salt was added making R2 0.18
15 lb of salt X 12= 180
180 / 0.016 = 1125 gallons of pond volume
by Norm Meck
reprinted from koiusa
Common Salt, Sodium Chloride, NaCI, has been termed
"The Koi Wonder Drug". A misnomer perhaps, but salt is a
proven staple in the health care and maintenance of Koi worldwide. Koi
maintain an internal concentration of salt in their body fluids higher
than that of their liquid environment. Osmosis causes water to transfer
from the lower salinity of the pond water into the tissues of the fish.
This additional water build up must be eliminated by the kidneys.
Although salt in higher concentrations may slow some disease causing
bacterial growth in the pond, the predominantly accepted theories
ascribe the primary benefits of salt to lowering the osmotic pressure.
This reduces the effort the fish must expend in eliminating the excess
water. The saved energy is then available for use by the fish's own
immune system to take care of other potential problems. The presence of
salt also helps counteract any nitrite toxicity. In some cold climate
areas, it is added in the winter to lower the freezing point of the
Salt can cause pond plant damage as the concentration
increases. Floating plants, (water hyacinth, water lettuce, etc.) are
affected at lower concentrations than most bog plants. Related, salt may
provide some partial control of algae in the higher concentrations.
The amount of salt dissolved in water is measured
either as a per cent, in parts-per-thousand (ppt), or in
parts-per-million (ppm) (where 10 ppt = 1% = 10000 ppm). The more common
parts-per-thousand measurement is the weight of the salt in pounds per
thousand pounds of water (about 125 gallons). Pond-keepers often talk
about the pounds of salt per hundred gallons of water. Since 100 gallons
of pure water weighs about 800 pounds, one pound of salt per hundred
gallons equates to a salinity of 1.25 ppt (0.125% or 1250 ppm). (1 ppt =
0.8 pounds per hundred gallons)
[Note: Koi internal fluid salinity is on the order of
15 ppt (about the same as ours) Sea water is around 35 ppt to 70 ppt
depending upon geographical location. The Great Salt Lake has a nominal
concentration of about 250 ppt.
There is some disagreement about salt in Koi ponds.
Our San Diego tap water often has a salinity of up to 0.5 ppt. This
amount cannot be tasted but we drink it and we put it into our ponds. If
our Koi were put into an absolutely pure (distilled) water environment,
the osmotic pressure would be so high that some would be unable to
eliminate the excess water and would die almost as if by drowning. On
the other hand, if the salinity approaches that of the internal tissues
of the fish, the osmosis process will decrease or even reverse. This can
cause the fish to die, essentially of dehydration. Any discussions
should therefore center not on should salt be in the pond but how much.
The addition of one to two pounds of salt per hundred
gallons of water (1.25-2.5 ppt) is recommended for most ponds,
especially in the spring and fall. This is a fairly conservative dosage
but without having a reasonable quantitative measurement method, higher
concentrations should be avoided. If nitrites are present, using three
to four pounds per hundred gallons (3.75 to 5 ppt)is appropriate to
reduce the nitrite toxicity. After the initial application, the dosage
applies ONLY to the amount of water being taken out and replaced, NOT to
the amount of water in the entire pond. and NOT to water being added to
replace that lost by evaporation. Except the very short-term medicinal
baths at concentrations often around 25 ppt (1 pound per 5 gallons), and
administered under tightly controlled conditions, it is not recommended
that Koi be subjected to a salinity exceeding 5 ppt (4 pounds per
hundred gallons), especially for extended periods.
The salinity is normally maintained by the addition
of salt to increase it and by water change outs to decrease it.
Introduce the salt. if possible, at the discharge side of the bio-filter
(not at the bio-filter inlet nor directly into the pond). If the
addition must be made directly into the pond, dissolve the salt in a
bucket of pond water and distribute it evenly around the edges of the
pond. Inquisitive Koi will check if any new addition to the pond might
be something to eat. Although they will probably not swallow the pieces
of salt, direct contact of crystalline salt with the fish for more than
a few seconds can cause injuries similar to burns. When making the
initial or any large application, it is probably better to divide it
into two to four daily panial additions rather than putting it in all at
(Note: Inexpensive and pure solar dried or kiln-dried
salt used in home water softeners is available at most supermarkets. Do
not use pelletized water softener salt that has binding agents or any
type of iodized salt.
I obviously am one of those who believe in adding
salt to my Koi ponds. I am also one of those who do not like adding
anything to the water unless I know what is already there. A pond-keeper
can keep records of salt added, water removed, and water added. But,
after a few water change outs, rain storms, and other water additions,
the resulting salinity is somewhere between questionable and unknown.
For some time, I have been trying to find a way to measure the amount of
salt in my ponds. A chemical laboratory can supply a quantitative
analysis, but this is both expensive and not very timely. Other than
very expensive reflectometers, the commercial salinity test kits and
other devices, available seem to measure in only two ranges. The first
is around 0-50 ppt, used for salt water systems and the second is around
0-100 ppm used for fresh water applications. Neither of these will
provide the accuracy needed over the range of interest. I would like to
maintain a concentration in the range from 2.0 to 4.0 ppt (I actually
use a target of three ppt or 2.4 pounds of salt per hundred gallons).
In cooperation with the LaMotte Co., a leader in
aquaculture testing products.., a modified procedure was developed for
use with one of their salinity test kits to provide a fast, inexpensive,
and highly accurate measurement over the desired range. The
"off-the-shelf' kit was designed to measure 0-20 ppt in 0.4 ppt
increments. Substituting the modified test procedure provided below for
the standard procedure, the range is changed to 0-5 ppt in 0.1 ppt
increments. The titrator supplied with the kit reads 0-20 and the result
is divided by four. An optional titrator, calibrated 0-50, can be
purchased and the result divided by ten, which is a little easier. It
probably makes little difference to the fish, but I feel better that I
can now make an accurate salinity reading.
As an example of the accuracy of this test and as a
secondary use of the test kit, a pond was found to have a 0.5 ppt
salinity measurement. It was desired to bring the level to 2.5 ppt, an
increase of 2 ppt. As the owner thought the pond contained about 3100
gallons, 50 pounds of salt was added (3100 divided by 125 times 2). The
next day, the salinity actually measured 3.1 ppt, or an increase of 2.6
ppt. Working backwards, this showed that the pond actually contained
only 2400 gallons (50 times 125 divided by 2.6). A later unfortunate
incident required the pond to be drained. When it was refilled through a
water meter, it was determined that the pond actually held just under
2500 gallons. The pond owner had been excessively medicating and
chemically treating the pond by almost 25%! It has been found that the
salinity test kit can be used to determine the amount of water in a pond
with an accuracy of about 5%.
If you purchase the test kit for use in the 0-5 ppt
range. use the following test procedure, (see insert) not the one
included in the kit.
The salinity test kit (Part No. 7459: about $35 for
50 tests), the refill kit (Part No. R7459; about $15 for 50 tests), and
the optional 0-50 direct reading titrator(Part No. 0380; about $5), are
available directly from LaMotte or, at an equal or slightly lower cost,
from one of their distributors listed below (or others). Prices do not
include shipping, and are, of course, subject to change. All will accept
major credit cards.
P0 Box 329
Chestertown, MD. 21620
166 Seven Oaks Road
Leland, MS. 38756
Aquatic Eco-Systems, Inc.
1767 Benbow Court
Apopkak, FL. 32703
Modified Test Procedure for LaMotte Salinity Test Kit
1. Rinse and fill the titration tube to the 10 ml
line with deminenalized water from the demineralizer bottle.
2. Rinse and fill the 1.0 ml Direct Reading Titrator
to the zero mark with the water to be tested. Wipe any excess water off
3. Dispense the entire 1.0 ml of sample water into
the titration tube. 4. Repeat steps 2 and 3 to add a second 1.0 ml of
sample water into the titration tube.
5. Add 3 drops of Salinity indicator Reagent A to the
titration tube. Cap and gently swirl to mix. A light yellow color will
6. Fill the 0-20 (or optional 0-50) Direct Reading
Titrator to the zero mark with Salinity Titration Reagent B. Insert
Titrator in the hole of the cap of the titration tube.
7. While gently swirling the tube, slowly depress the
plunger until the yellow color changes to pink-brown. 8. Read the test
result where the plunger tip meets the scale on the calibrated titrator.
9.If using the 0-20 titrator supplied with the kit,
divide the reading by four (i.e. if the titrator reading was 9.2, the
result is 2.3 ppt). If using the optional 0-50 titrator, divide the
reading by ten (i.e. if the titrator reading was 23, the result is 2.3
(Note: The demineralizer bottle can be refilled with
tap water or even pond water but the deionizing resin bed will last
longer if distilled water is used.
Note from Chuck: I have this kit but I have
also seen a nice test kit at Pet supermarket by Pond care: