Page 32 - Commercial Catalogue 2011

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27 Commercial Catalogue
Tel: +44 (0) 1923 284151 www.tropicalmarinecentre.co.uk
Application Level Comparable Livestock HoldingApplications
Stocking Density Tropical Species Temperate Species Coldwater Species
(wet weight)
25-27 o C
18-20 o C
13-15 o C 6-8 o C
Ornamentals Research Aquaculture
No. of units req’d No. of units req’d No. of units req’d
1
Display
Larval
Incubation
< 1 kg/m
3
0.25
0.3
0.4
0.5
2
Retail
Juvenile
Hatchery
1 – 2 kg/m
3
0.40
0.5
0.6
0.7
4
Wet Lab
Nursery
6 – 9 kg/m
3
2.0
2.5
3.0
3.5
5
Growout
10 – 15 kg/m
3
3.0
4.0
5.0
5.5
How to calculate the number of units needed to filter a different water volume at a different
application level and/or temperature range:-
1.
Choose item from the relevant pricing table
e.g 7910 FST 5200A Fluid Sand Filter, and note the
maximum system volume at application level 3 e.g 10,000 litres.
2.
Divide your actual system volume by maximum system volume to determine the number
of units required
e.g 20,000 litres 10,000 litres = 2
3.
Find your actual system application level from the table below
e.g Retail/Juvenile/Hatchery or
refer to the stocking density.
Then, read across row to the factor given under your
appropriate temperature range
e.g Retail, 25-27
o
C = 0.4.
Multiply this figure by the number
calculated in 2 above to determine the appropriate number of filter units recommended
for your application.
• If the calculated value is
less than 0.5
then check if there is a smaller unit available from our range.
• If the calculated value is
between 0.5 and 1.5
then one unit will be required.
• If the calculated value is
more than 1.5
then up to two units will be required.
• If the calculated value is
more than 2.5
then check to see if there is a larger unit available from our range.
Biological Filtration:Choosing the Correct Biological Filter
Biological filtration refers to filtration methods that utilise living organisms to neutralise or remove
undesirable substances from a process liquid. It is the removal of waste metabolites that would
otherwise accumulate from keeping, feeding and growing aquatic animals in a closed recirculating
system that is considered here.After oxygen, it is the accumulation of ammonia - the waste
metabolite from protein digestion - that is probably the most limiting factor affecting the successful
operation of closed recirculation systems.The removal of ammonia (NH
3
) by oxidation to nitrite
(NO
2
) and finally nitrate (NO
3
) is carried out primarily by the bacteria
Nitrosomonas sp
. and
Nitrobacter sp
. respectively.This process is called NITRIFICATION. Un-ionised ammonia and nitrite
are both toxic to fish at relatively low concentrations whereas nitrate, the end product of
nitrification, is relatively non toxic at even quite high concentrations.The rate of nitrification is
proportional to temperature, proceeding particularly slowly below 10
o
C, and is optimal around
30
o
C. However the metabolic rate of aquatic animals is also proportionately lower at reduced
temperatures and it is perfectly feasible to consider recirculation at cooler temperatures.
The particular size and type of filtration equipment for a given application will depend on a number
of factors including, but not limited to, the type of livestock being held, the total stocking density, the
amount of food that is added to the system and the temperature of the water. Use the table below
to calculate which size of a particular piece of equipment your application will require.
Most of our biological filters are sized for a given water volume to be filtered at application level 3
and at a tropical temperature range.
3
Wholesale
Adult Broodstock 3 – 5 kg/m
3
1.0 1.1
1.5 1.7
.
.
Application Level Comparable Livestock HoldingApplications
Stocking Density Tropical Species Temperate Species Coldwater Species
(wet weight)
25-27
o
C
18-20
o
C
13-15
o
C 6-8
o
C
Ornamentals Research Aquaculture
No. of units req’d No. of units req’d No. of units req’d