Koi Medic Salinity Meter Pen

Common salt, sodium chloride, NaCl, has been termed "The KOI Wonder Drug". 

Koi maintain an internal concentration of salt in their body fluids higher than that of their liquid environment. 

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. 

Using it at a .6% - .7% level is excellent when bringing in new fish to a quarantine tank. Salt is effective on all microscopic parasites at this level. 

For informational purposes here is how to calculate salt:

.1% salt in 100 gallons is .8333 pounds - 1% salt in 1000 gallons is 8.333 pounds.

.3% salt in 100 gallons is 2.5 pounds - .3% salt in 1000 gallons is 25 pounds.

.6% salt in 100 gallons is 5.0 pounds - .6% salt in 1000  gallons is 50 pounds.

.15% salt in one ton(264 gallons) is 3.313 pounds.(preferred for reduced nitrite uptake)