In all marine systems wastes are continuously produced. Fishes secrete most of the food in form of ammonia/ammonium (= NHx), protein, amino acids and fibers. To prevent fish and other animals against toxic concentrations, these substances must be eliminated or changed into harmless material. With biological filtration almost every substance may be converted into carbon dioxide, water, nitrate, phosphate and sulphate - mineralization. But these products accumulate. With skimming or flotation proteins and some other substances are taken out of the system before the biological filtration works. The raising of nitrate and phosphate lowers with skimming. The water has lower concentrations of biological oxidizing substances. So the redox (ORP) is higher and the animals grow better. If high concentrations of organic matter occur (death of an animal, too much food), a biological working filter reacts very slowly. Bacteria must adapt to the new input. Especially nitrifying bacteria Nitrosomonas and Nitrobacter need a long time to react to the new concentration. The flotation process reacts automatically and prevent a rising of toxic products like NHx and nitrite. By using a skimmer the conventional filter technique (sand filter, trickling filter, biological filter) may be laid out smaller. Investment (smaller filter), running costs (flushing water) and need space are minimized.
Principle of Flotation:
The process water is pumped through the injector that takes air into the water. The air-water- mixture is injected at the lowest point of the skimmer into the rotation chamber. Here the system pressure is high to enable maximum gas change (oxygen input, carbon dioxide output).
After a while the gas-water-mixture up flows the inner tube. There the organic loaded foam is created. A part of the bubbles goes downwards the main tube. In this tube the water stream downwards is as high as the velocity of the bubbles upwards. So the bubbles are caught for a long time - long contact time. At the bottom of the AquaCareFlotor the main tube enlarges to inhibit the bubble going out of the water outlet. The foam in the upper parts looses water and is pushed into the foam cup. With this system high amounts of organic loads will get out of process water.
AquaCare® is building flotation systems (Juelicher Principle****) from 0.2...420 m3/h. The smaller units are available with three different air bubbles producing systems: version “V” is built with a venturi, version “A” with air stones, and version "N" with a needle wheel. The field of application is hobby size sea water aquaria and labs. The medium and large models are exclusively equipped with venturi / injector and their field of application is:
aquaristic purpose:
show size reef and shark tanks
large predator tanks (sharks)
dolphinaria
seal tanks
tanks for tropic ornamental fishes
aqua culture:
fish breeding
shrimp farms
keeping of sea animals for scientific centres
**** this principle was invented by Research Center Jülich GmbH, Germany (former Nuclear Research Centre)
Advantages of the suspended flow method:
extremely long contact time between the air and the sea water resulting in:
high enrichment with oxygen
strong formation of the carbon dioxide / hydrogen carbonate / carbonate buffer (alkalinity)
more even pH value
higher ozone transition (reduces the needed ozone input up to 70% compared to conventional systems)
smaller than already available skimmer
low running costs (only one pump for injector and water flow)
sensitive to protein concentrations (BSA) of as low as 3 µg/l (operation with ozone)
lowers the numbers of free-swimming bacteria to about 20%
only one pump for driving the injector and for the water flow through the system
Advantage of the AquaCareFlotor:
reduced size
maintenance is more easier
optimized injector with a working pressure of 1 to 2 bar creates smaller bubbles
large turbulence zone
enlarges efficiency and power
any chalk creation (up to 10°dKH at 25°C)
high air inlet pressure and flow
magnetic coupled pump
any leakage possible
low heat input (important for cold systems)
build in accessories:
air flow meter
flushing system in foam cup
ozone connector
angle seat valve for air input
angle seat valve or butterfly valve with hand gear for water regulation
additional connector for units like chalk reactors, nitrate filter (systems that need small water volume at high pressures)
connector for ORP (redox) probes
it is possible to demount the injector
recycling of the used exhaust air that contains ozone (starting with model ACF16000V)
options:
activated carbon filter for air input
activated carbon filter for destroying ozone in the air outlet
de-aeration chamber for bubble free outlet water
flow meter for water inlet (mechanical or electronical)
cycling of the skimmer water (model "C") for extreme loaded water or for bacteria elimination (see de-nitrifying)
insulation (model "I") for extreme cold water systems
ORP control for automatic dosing of ozone
automatically level control with PLC at extremely variying water quality
obtainable as external module or for immersion in the tank
The right design depends on many factors: organic load (stocking), food, temperature, species, additional technique like biofilters, UV, ozone and of course the wishes water quality. Please ask if you are not sure what is the right size for your tank. * The recommended ozone input is for normal reef tanks - the skimmers work without ozone, too. If you have very strong organic loads (aqua culture, sea mammals, sharks, bacteria destruction) a manifold is possible. Please ask AquaCare®. ** It is possible to fix the pump onto the ground plate; if not the ground plate might be shorter (ask AquaCare) *** MX, MDX, MDE and MDR are IWAKI pumps (optional), KR are ARBO pumps (optinal). All sizes up to ACF480.000V fits in standard containers or normal trucks. Larger sizes needs a special transport.