Family's aquaculture experiment passes taste test 



Not everything that grows in the 

 Moores' greenhouse is green. Just past 

 the salad greens and vegetable seed- 

 lings is a 550-gallon tank. And inside 

 swims a crop with gills, fins and an ap- 

 petite for algae. 



There's a bit of the pioneer in Joyce 

 and Allen Moore. Aquaculture, for 

 them, has been part experiment and 

 part adventure. They've had a few 

 setbacks — cold water, periods when 

 the fish wouldn't grow, a clog-prone 

 clarifier — but lately things are looking 

 up. And this spring, their experiment 

 passed its stiffest test when the Moores 

 sat down to their first plates of home- 

 grown tilapia. 



"They were pan-size, with good tex- 

 ture and few bones," Joyce says. "The 

 meat itself was very good. They tasted 

 faintly of algae around the gut cavity, 

 but we should be able to eliminate that 

 problem by reducing the algae popula- 

 tion and by holding the fish in fresh 

 water for a day or so before we clean 

 them." 



The Moores' 8- by 20-ft. green- 

 house, finished in 1980, adjoins the 

 south side of the house they built 

 themselves high in the mountains of 

 Jackson County, N. C. Allen, who 

 teaches biology at Western Carolina 

 University in Cullowhee, supplies 

 some scientific knowhow to their 

 homesteading. Joyce, a weaver, is 

 home enough to keep an eye on things 

 and to make sure their garden, green- 

 house, orchard and livestock stay 

 productive. The Moores feel that food 



Photo by Laurel Hort 



is best and safest when it is fresh and 

 homegrown. And that's one reason 

 they've turned to aquaculture. 



"We're definitely interested in food 

 production," Joyce says. "And 

 aquaculture is an efficient way of 

 producing good protein." 



Allen says that fish-farming and 

 greenhouses are natural companions. 

 Efficient solar greenhouses, he ex- 

 plains, use some kind of massive 

 material to absorb excess solar energy. 

 This heat sink can radiate warmth into 

 the greenhouse as things cool off at 

 night. And water is one of the best 

 materials for storing heat. 



"We needed five hundred gallons of 

 heat storage in our solar greenhouse," 

 Allen says, "so we thought, why not 

 raise some fish in that water?" 



Simpler said than done. First came 

 reading and questioning that led them 

 through piles of books and numerous 

 interviews. A workshop at Haywood 

 Technical Institute last year put them 

 in touch with aquaculturists around 

 the country. 



They learned a lot about the 

 biological problems they faced, but 

 found information sketchy on the new- 

 fangled idea of raising fish in home 

 greenhouses. Much of their system's 

 design is original and its components 

 are mostly homemade, though they 

 did get some professional help shaping 

 the fiberglass fish tank. 



"There's really nothing in the books 

 that duplicates our system," Joyce 

 says. 



The Moores' greenhouse looks south over mountains 



She designed the biological filter for 

 the system herself, using a length of 

 perforated drain pipe, partly filled 

 with gravel, to aerate and detoxify the 

 water. In the Moores' design, water 

 drawn from the bottom of the fish tank 

 is pumped into a clarifier, a plastic 

 tank packed with a filtering medium to 

 catch sludge. Cleared of most solids, 

 the water is piped over the biological 

 filter, where bacteria in the gravel do 

 the rest. 



"As far as we can tell, the water 

 quality is good," Joyce says. "The best 

 news was the lack of crud on the bot- 

 tom of the tank when we drained it 

 recently (to patch a leak). I think we 

 can easily increase the quantity of fish 

 without over-extending the system's 

 carrying capacity." 



The Moores stocked 50 tilapia fin- 

 gerlings last spring. The largest have 

 been eaten, and Joyce says they are 

 thinking of adding catfish to cohabit 

 with the tilapia. They hope the catfish 

 will grow better during cool weather. 

 The tilapia, which grow fastest when 

 water temperatures are around 80° F, 

 stopped growing altogether when tem- 

 peratures in the tank dropped to 42° F 

 last winter. The fish tank didn't hold 

 quite as much heat as the Moores had 

 hoped it would. 



"We actually did have to heat the 

 water some this winter, when the tem- 

 perature outside at night went down to 

 minus six or minus seven," Joyce says. 



The problem could be solved by in- 

 stalling a heater, but the Moores are 

 trying to keep things simple, low-cost 

 and energy-efficient. 



"You could easily have a net loss of 

 energy if you used a heater all winter," 

 Joyce says. She's hoping they can ad- 

 just things in the greenhouse and make 

 better use of free sunshine. 



Other problems with the system will 

 have simpler solutions, the Moores 

 believe. The Moores have concluded 

 that the polyester fabric they had used 

 in the clarifier was too closely woven. 

 Acting on the advice of Johnny Foster, 

 one of Sea Grant's aquaculture ex- 

 perts, they have recently installed bird 

 netting in the clarifier. Now they're 

 planning ways to reduce algae which 

 have grown faster than the tilapia can 

 eat them. (The tilapia have also been 

 fed a commercial trout feed.) 



