GLENOLDEN -- People who buy boats and tropical-fish aquariums have one thing in common: The first purchase is never big enough. Boaters, though, sell before they upgrade. Fish hobbyists simply add a tank, then a larger one, and still another until some reach a point where, like Bob Kulesa of Glenolden, their home becomes one vast aquarium.

"It's a hobby that mesmerizes the collector," said Kulesa, 56, a retired Philadelphia schoolteacher who boasts 50 tanks with hundreds of tropical fish in his home. Kulesa is a longtime member of the Delaware County Aquarium Society and the editor of its monthly publication, Fin Fax. He breeds and raises a variety of fish, specializing in the killifish, a rare and colorful small-stream fish native to inland regions of Brazil and Africa. He also has five outdoor ponds, one of which resembles a miniature rain forest with a waterfall, stands of tall reeds, dwarf bamboo, water lettuce, and floating plants. None has been stocked this season, Kulesa said, because recent surgery has restricted his activity. In time, he plans to move some of his indoor specimens outside and perhaps add some exotic koi, a Japanese carp prized for its color.

Meanwhile, Kulesa dutifully monitors his indoor tanks, attends the society's monthly meetings in the Springfield Township municipal building and touts his hobby to anyone who will listen. "Studies have shown that the presence of aquarium fish has a certain calming effect on people and can even lower blood pressure," Kulesa said. "That's why you find them in dentists' offices and nursing homes."

Another society member, Ed Keene of the Briarcliffe section of Darby Township, also breeds and raises fish, but he's something of a piker with only 19 tanks, three of which are show quality. One took first prize at the aquarium society's annual home-tank show this year. Keene, the society's new president, said that the organization was 43 years old and had about 140 members from Delaware County and the surrounding tri-state area.

It began in 1956 as the Piasecki Helicopter Co. Aquatic Club in Springfield, with membership made up of employees of what later became the Boeing Vertol Co. In 1956, when interest and membership spread beyond the plant, the club changed its name to the present one. Keene, 48, said he got started in tropical fish as a child, like most members, then gave up the hobby. He came back to it after his two children were born.

A subsequent divorce brought crisis to his life, he said, and he credits his hobby with providing both a catharsis from pain and a distraction from the loneliness of an empty house. "It may be hard for some people to understand, but I still find an inner peace sitting in front of my tanks and watching the fish," Keene said, likening it to the joy of owning a dog or cat.

Kulesa began his hobby as a child growing up in Clifton Heights and took a rain check during college and marriage. He resumed at the suggestion of his wife, Nathalie, who said she didn't mind the tanks and fish in her basement. "At least I know where he is," she said.

Joseph Yanik of Downingtown, the society's past president, said that many members had installed outdoor ponds to better "condition" their fish and that stores such as Home Depot were selling ready-made kits. "Outdoors is the natural state for all fish, and a month or so in sunlight, feeding on insect larvae, improves the size and color of tropicals," Yanik said. But there are problems with ponds, as one Chester County member found.

Bruce Ossman, the proud owner of a large goldfish pond on his two acres in West Chester, said he lost his biggest fish to a blue heron last year. "I looked out the kitchen window one morning and did a double-take," he recounted. "There was this big heron with a long, pointed bill stalking alongside my pond. Before I could move, the bird dove into the pond, came up with the goldfish, and swallowed it head-first after shaking it into position." Ossman, who keeps about 50 fish in his pond, said he once found a small snapping turtle in the pond. His advice to prospective pond owners? "Just be aware that you're easy pickings to a lot of critters and insure your koi," he suggested.

For More Information: To learn about the Delaware County Aquarium Society or join the club, call Ed Keene at 610-586-7250 or Bob Kulesa at 610-534-5935. © 1998 Philadelphia Newspapers Inc.

CAPE MAY POINT, N.J. - OK, so it wasn't exactly the kind of fish you would mount on the wall or boast about later to the gang at the local watering hole.But try telling members of the Delaware County Aquarium Society that they should forget about the nine-inch freshwater white perch they found on Saturday in Lake Lily, about a five-minute walk from the Atlantic Ocean.

"That's the biggest fish we've ever caught in here," said Bob Kulesa, of Glenolden, Delaware County, as he peered into the bucket where the fish splashed around Saturday morning before the group released it about 45 minutes later.

About a half-dozen fish lovers from the Aquarium Society got up before dawn to make the nearly three-hour drive from Philadelphia's western suburbs to the southernmost point of New Jersey, as part of an annual pilgrimage to keep tabs on a lake that has seen better days.

Lake Lily, a natural freshwater lake about one mile around, sits closer to the ocean than nearly any other decent-size body of freshwater around, Cape May Point residents say. Years ago, people swam in it, fished in it, boated on it and generally used it as a respite from the salty waters of the Atlantic or the Delaware Bay, which surround the Cape May peninsula. A variety of birds, including cranes and herons, make it a stopover while migrating north or south through New Jersey.

Lately, though, the fish population has plummeted, and it has seemed as though Lake Lily might be dying. Muck has piled up on the bottom, long droughts have made the water inhospitable to any but the smallest fish, and some of the birds that used to snack here on their way through have ceased dropping by. The lake takes in drainage from the nearby roads, which also hurts its inhabitants.

So when the Aquarium Society - which has been going out to Lake Lily once a summer for the last six years - found the big perch and several other slightly larger fish than they had spotted in previous trips, members took it as a sign that the ecosystem in the lake might be getting back to normal. "You can see it's got wonderful potential - I mean, my God, this is gorgeous," said Bob Kolimaga, of Paoli, Chester County, who organized the trip.

The Aquarium Society, which has about 75 members at its monthly meetings, started going to Lake Lily for its admittedly unscientific surveys of the environment when a colleague of Kolimaga's who lives in Cape May Point asked him if he knew anything about fish and would like to check out the lake.

On Saturday, the group dragged nets through the brownish water of the lake to look for fish, stumbling through two-inch mud deposits on the bottom and steering clear of snapping turtles. Members also tested the water's pH balance, hardness and salinity before making a report over lunch to several volunteers from the Cape May Point Environmental Commission.

Though they took solace in the size of some of the fish they found, the lake still seemed populated mostly with small killifish and sticklebacks, with only a few fish big enough for birds to live on. Even the lake's namesake aquatic plants are scarce.

"That's how it got its name, because of all the lilies," said Cape May Point resident Toni Keiser. "It doesn't live up to its name anymore." Cape May Point is pushing New Jersey officials to dredge the lake and help its fishy inhabitants out, but a bill to cover the $650,000 cost of the project is languishing in the state Legislature, said Nancy Kirtland, who cochairs the borough's Lake Lily committee.

Though the Cape May Point residents and the Delaware County Aquarium Society members bandied about some possible solutions to the lake's problems, the trip really seemed to be mostly about having a good time, since the Aquarium Society folks freely and cheerfully admitted they didn't have the right training to do much about the lake's condition. While eating their hot dogs, baked beans and potato salad, they spent time talking about the different types of fish they had seen and how to identify them. Some members kept sample fish to take home to backyard ponds. One of the club's youngest members, 15-year-old Chris Guarino, a sophomore at Malvern Preparatory School in Chester County, offered some of the most definitive-sounding theories about the lake. Armed with an astounding amount of information about marine wildlife, Guarino spoke of how the food chain appeared to be awry.

"This is a good club," said Allentown resident Barbara Moyer, a professional aquarium tank technician who joined the Delaware County bunch after the Lehigh Valley club she founded shut down a few years ago. "Some of the clubs get cliquey and snobby - they're in it for the ego, they're in it more for the glitter and the glamour." If one thing was clear, though, it was that Saturday's trip was not about glamour. "We certainly enjoy coming here," said Richard Kerr, another member, from Haverford. "We never know what to expect."

Mike Madden's e-mail address is mmadden@phillynews.com