278 FISH HATCHERY MANAGEMENT 



Recommendations for its use vary from 2 parts per million (5.4 pounds 

 per acre- foot) to as much as 8 parts per million (21.6 pounds per acre-foot) 

 as an indefinite pond treatment. At 2 parts per million it is not toxic to 

 catfish or centrarchids, but it can be very toxic at greater concentrations 

 unless there is a significant amount of organic matter in the water. There- 

 fore, before a concentration higher than 2 parts per million is used, it is 

 imperative that a bioassay be run with both fish and water from the unit to 

 be treated. In most situations, it is best to use 2 parts per million even 

 though the treatment may have to be reapplied within 24 hours to be effec- 

 tive. 



It has been recommended that 3 parts per million be used to treat trout 

 with excessive gill proliferation associated with chronically poor environ- 

 mental conditions. However, as in all cases, it is best to test this concentra- 

 tion on a few of the trout before it is applied to the entire lot. 



Potassium permanganate imparts a deep wine-red color to water. Upon 

 breaking down, the color changes to dirty brown. If a color change occurs 

 in less than 12 hours after KMn04 has been applied, it may be necessary 

 to repeat the treatment. 



Potassium permanganate also is used widely to help alleviate oxygen de- 

 ficiencies in warmwater ponds. Although it does not add oxygen to the 

 water, as has been suggested by some, it does help reduce biological oxy- 

 gen demand by oxidizing organic matter in the pond. 



QUATERNARY AMMONIUM COMPOUNDS 



Quaternary ammonium compounds are not registered by the Food and 

 Drug Administration. Such chemicals as Roccal, Hyamine 3500, and Hy- 

 amine 1622 are bactericidal but will not kill ectoparasites. They generally 

 are used for controlling external bacterial pathogens and for disinfecting 

 hatchery equipment. Like many chemicals used in external treatments, 

 they become more toxic at high temperatures and in soft water. The 

 quaternary ammonium compounds commonly are used to treat salmonids 

 for bacterial gill disease. A standing bath of 2 parts per million (active in- 

 gredients) of Hyamine 3500 or Roccal for one hour usually is successful. 

 Hymane 1622 has been used by some culturists who find Hyamine 3500 

 too toxic for salmon fingerlings. Treatments should be conducted for 3 or 4 

 consecutive days. 



Quaternary ammonium compounds may be purchased as liquids of vari- 

 ous strengths. A 50% solution is an excellent consistency to use but, when 

 exposed to air, it may evaporate, changing the concentration. Hyamine 

 1622 may be purchased as a 100% active-ingredient powder that goes into 

 solution easily when added to warm water but tends to form a sticky mass 

 if water is poured over it. A respirator should be worn when this com- 

 pound is used. 



