Inland Aquaculture Engineering (1984)
 DESIGN OF FISH HATCHERIES
 Chapter 12 Planning of Fish Hatcheries
 (introduction...) 1. BASIC DATA 2. PROCESSING OF BASIC DATA 3. CALCULATION OF WATER REQUIREMENT OF A FISH HATCHERY 4. TEMPERATURE REQUIREMENT OF HATCHING 5. TECHNOLOGICAL DESIGN 6. CONNECTED FACILITIES

### 3. CALCULATION OF WATER REQUIREMENT OF A FISH HATCHERY

Guiding numbers of technological water requirement of hatching are the following:

7 l size hatching jar: see Figure 1
10 l size hatching jar:

for hatching common carp 0.7 ... 2.5 l/min pc jars

50 l size hatching jar:
for hatching grass carp, silver carp and bighead carp 0.4 ... 2.5 l/min pc jars

170 l size larval rearing tank:
both for larvae of common carp and for larvae of Chinese carps 3 ... 9 l/min pc tanks

Breeder tanks: 1 l/min . kg of breeder.

In the hatchery given in the above example the following water requirement is needed:

a) Requirement of water

For hatching

min. water 0.7 l/min . pc . 32 pc = 22.4 l/min
max. water 2.5 l/min . pc . 32 pc = 80.0 l/min

For larval rearing

min. water 3 l/min . pc . 16 pc = 48.0 l/min
max. water 9 l/min . pc . 16 pc = 96.0 l/min

For breeders

males 14.4 kg . 1 l/min . kg = 14.4 l/min
females 50.9 kg . 1 l/min . kg = 50.9 l/min
total 14.4 + 50.9 = 65.3 l/min

The highest simultaneous water need:

80.0 + 96.0 + 65.3 = 241.3 l/min 15 m /h

b) Requirement of water volume

Water requirement is calculated to the maximum requirement of water for safety reasons. Data concern 5 million larvae.

For hatching

 Duration of hatching: 3.5 d = 84 h Water needs: 8.0 l/min = 4.8 m3 . h Water requirement: 84 h . 4.8 m3 . h = 403.2 m3

For larval rearing

 Duration of larval rearing: 3.5 d = 84 h Water needs: 96 l/min = 5.76 m3 . h Water requirement: 84 h . 5.76 m3 . h = 483.8 m3

For keeping of breeders

 Males Duration in the hatchery 2.5 d = 60 h Water needs: 50.9 l/min = 3.054 m3 . h Water requirement: 72 h . 8.054 m3 . h = 219.9 m3 Total: 403.2 m3 + 483.8 m3 + 51.9 m3 + 219.9 m3 = 1 158.8 m3

As the calculations were made for the maximum water flow, the received number can be rounded to 1 000 m3. Thus, for 1 million 3.5 days-old larvae of common carp one can calculate 200 m of water.