how do you calculate gallons of water per fish? how do you deal with a closed system in relation to the growth of the fish, hormon secretion, parasites and disease associated with crampted quarters? the only issues i've seen addressed are the nitrification cycle and the conversion of ammonia to nitries to nitrates with nitrosomas and nitrobactor bacteria. (many other types of bacteria also help in the process such as aeromonus) also as discovered with the living reef wet dry systems, the bacterial pulled nutrients from the water to perform their task such as calcium, coral is a good buffer and it also provided the calcium the large bacteria beds needed.

if you add fresh water to the system, what is the dilution factor and still be able to maintain sufficient nutrients for the plants. i use taro floating (gets about 4-5' tall) in the koi pond system to stabilize the system, it contains 2500 gals with 13 koi ranging from 18" to 36", all are about 4 yrs old and two yellow belly slider turtles (female 14", male 10" got them when they were the size of a quater 19 yrs ago, but then the system is also an open system. a closed system would never have allowed the growth of the koi or the good health that they have enjoyed.

richard