Multivis recirculated fishfarming: systems and products

glasseelsystems    fattening eels


glasseels resting   sorteren   fat eels

Glasseels on a resting grid.........some time later.....              Grading, some time later.....                                 Fat eels on a resting grid


turbot behind the dykes   feeding turbot

Turbot behind the dyke, near the Waddensea                                                             Feeding turbot


New systems

From 1984 Multivis specialized in recirculated systems for species as eel sturgeon, trout, catfish and turbot. The recent systems have many innovative
features and a very low energy demand. The pictures below give some info about two different systems which were quite new for Dutch ras.

A) Horizontal ras with: discfilters as a microscreen, moving bed filters as a biological filter, strippers, propellerpumps and deepshafts, all in a horizontal line
with a head of about 0,5 m. The right picture shows the installation of polyester deepshafts. Deepshafts are oxygenreactors which are fed by propellerpumps.
The advantage of a deepshaft ( 30-40m deep ) is that you can reach high saturationlevels with a pump head of only 0,5-1m.

discfilters   deepshafts


B) The second system is a system with a tricklingfilter and a low head oxygen reactor (LHO ). This system has the following advantages:

1) It is fast and easily built in a prefab way,
2) Mounting in existing buildings is possible and it has no big concrete constructions and no tubes underground,
3) The big waterflow produces the highest removal of sludge and CO2 from fishtanks,


LHO   glasseels

 Glasseelmodule, built in two weeks by two men ( Italy )                                              Glasseels on a relaxgrig, fast growth, FCR<1

4) The tricklingfilter has the advantage ot the combined aeration and removal of CO2 and N2 ( stripping ).
5) Trickling filter material is constant in air and has the lowest risk of oxygen depletion at power cut.
6) There is no risk of N2 oversaturation.
7) One way pumping wit a head of ca  6 m. No pressure pumps on oxygencones. This system probably has the lowest costs of energy.
8) Material: only quality stainless steel and plastic, with the highest return of investment. 
9) In addition the system is very simple in design and operation.

It is the smartest way to give your fry the first fast boost!

lho zij   oxygendosing

Temperature, pH and Oxygen are regulated automaticly

From fishtanks (1) the flow is on gravity to a drumfilter (2) to the pumptank (3).  From (3) the water is pumped to the tricklingfilter (4) and than it flows on gravity through the LHO (5) and back to the fishtank (1)