By far the most problematic parasite that the Tennessee Aquarium has had to manage in its fish collection is a peritrich ciliate Heteropolaria sp. This sessile parasite, formerly placed in the genus Epistylis, was first detected in the Tennessee Aquarium's largest exhibit in the spring of 1994. While the ciliate's method of introduction was not determined, two strategies were undertaken in 1995 to eradicate it from the exhibit: 1) all fish (approximately 450) were removed from the exhibit and placed in a salt solution (5-8 ppt NaCl for 21 d) and 2) the empty exhibit was treated for 21 d with salt solution (NaCl) at a concentration range of 12-15 ppt. This latter treatment was facilitated by renovation of the exhibit in January, 1995 because the renovation provided a good opportunity to attempt a more thorough treatment than at any time since the parasite was initially discovered. Fish were removed and isolated in several quarantine systems. Over 90% of the known infected fish were centrarchids, a trend similar to that seen in several other exhibits at the Aquarium. Heteropolaria was not detected on any specimens from the re­established display for a period of eight months. A low level infection was confirmed in the exhibit in mid-October, 1995 and salt therapy commenced. A total of 4,536 kg of Morton brand food grade salt was dissolved in the exhibit, which remained on-line and fully stocked with animals. A therapeutic concentration range of 4-7 ppt was maintained for 5 weeks. Within one month after termination of the salt therapy Heteropolaria was again detected in the exhibit. The infection had been reduced to a lower level throughout the exhibited fish community but complete eradication was not achieved. Further management of the parasite involved removal and treatment of specific individuals that were noticeably infected. In some cases topical application of a 1% iodine (Povidone) solution on affected areas was used in conjunction with salt therapy.