Salting away tips on seawater aquariums.

Almost every kid has had a freshwater aquarium, stocked with the usual goldfish and guppies.

But for adults who have maintained an interest in fish as pets, the expectations and rewards from their hobby--along with their tastes--may have grown a bit more elaborate.

Enter the saltwater aquarium, a high-tech version of the ordinary fish tank whose upkeep requires more skill, more money, a basic knowledge of sophisticated aquarium-keeping techniques and a little more patience to maintain.

But the rewards too can be greater: the psychic satisfaction of mastering the mechanics of seawater aquariums, as well as the visual beauty of the rainbow variety of marine life they offer, including brightly hued tropical fish, sea anemones, starfish, crabs, and other aquatic plants and animals that normally subsist only in the briny deep.

At the Cabrillo Marine Museum on Saturday, 13 amateur aquarists with a passion for tropical marine life gathered for a class led by Lloyd Ellis, the museum’s chief aquarist, on how to set up, stock and maintain seawater aquariums.

The class included some basic tips on the technical aspects of seawater aquariums, such as the use of hydrometers to measure salinity and dechlorinators to transform ordinary tap water into aquarium-ready freshwater. After the water is dechlorinated, a synthetic sea salt is added to bring the water to proper salinity.

The six-hour class also included such practical tips as how to tell a sick fish from a healthy one (avoid fish that are sluggish or appear battered, Ellis advises).

Art Bernstein, an attorney from West Los Angeles who has maintained a saltwater aquarium for three years, said he set it up by trial and error after reading several books on the subject--and “lost a lot of fish in the process.”

Bernstein was at Saturday’s class “to pick up some pointers,” he said. “I used to have a freshwater tank but these are much more fun. The fish are brighter and much more colorful.”

Claremont teacher Elaine de Wet, attended the course with her daughter, Kathy, an underwater photographer. De Wet said that the course had given her ideas to take back to her sixth-grade classroom to incorporate into her science curriculum and that the museum will be a destination for a class field trip next school year.

Steven Maier, a physician, said that he has had a fish tank sitting empty in his house for three years and that maybe the class would give him the inspiration to set it up “pretty soon.”.

As a medical student in the Philippines, Maier said, he kept a saltwater aquarium with moray eels and other marine life in it, but the creatures died when his girlfriend put in a decorative seashell that seeped a poisonous dye into the water.

“It’s a good idea to find out the right way to do it,” Maier said. “When you walk into a pet store there’s so much equipment to choose from. . . . I have a B.A. in biology, but I don’t know if it prepared me for this.”

Preparing amateur aquarists to confront the often bewildering array of equipment needed to set up saltwater aquariums is one aim of the class, instructor Ellis said.

Ellis provided students with a list of the basic equipment needed, from the tank itself to a synthetic seawater kit, special sand or marine gravel for the tank bottom, carbon filters, air pumps, tubing and special thermometers.

Ellis discussed the science of seawater aquariums--including the advantages of natural material such as sand and ground oyster shells for filtering bacteria, compared to dyed or synthetic materials. But the class focused mostly on practical maintenance tips.

“Even a subtle thing like putting your hand in the tank, if you have on hand lotion, over a long period of time can affect the quality of the water,” Ellis said. “If you’re going to spend $10, $15 or $20 on a fish, you don’t want them to die.”

Museum aquarist Jeff Landesman, assisted Ellis in teaching the class, setting up a saltwater aquarium to show the students how it is done.

Students also toured the museum’s own seawater tanks, which are now dismantled while a water refrigeration system for storing the seawater is replaced. The rest of the museum, including scientific exhibits and slide shows, remains open, a museum spokesman said.

Many students said they came away with a renewed appreciation for marine life.

Ed Lai, a Torrance engineering manager, said his 10-gallon seawater tank is a constant source of wonderment to his two children--even though his youngest daughter is only 4 months old. Lai, who said he keeps sand crabs, scorpions and starfish in the aquarium, said he too is constantly amazed by the unending variety of sea life.

“I’m inclined toward nature,” Lai said, “and to be able to observe sea animals in your home where you can watch their behavior over time, that to me is very satisfying.”