Cleaning of a lake at Holme Olstrup on Zealand.
BiosaHerb Biofilter
Cleaning of a lake at Holme Olstrup on Zealand.
Biofilter in pallet tank.
At the bottom 10 cm pearls.
Covered with fibre cloth.
20 cm "Perlite" (Greek porous rock that is so porous that it can be used in Lifebelts and for insulating houses) + fibre cloth
30 cm Quartz sand, (of the same quality as used for sandblasting surfaces), covered with fibre cloth.
30 cm large Leca balls, covered with fibre cloth
The rest is filled with coarse wood chips.

Buffer tank for water 1000 liters is filled with lake water via on and off timer. A few times a day, excess water flows back to the lake via hose.


The water flow from the lake to the filter system is calculated at 1000 liters per 5000 m3 of lake water per day.
The flow through the Biofilter proceeds slowly over 18 hours, the last 6 hours dry out the filter, the bacteria grow and are ready for the next filling.
Very slowly, excess nutrients from the lake are eaten by the microorganisms and the lake gets clear water.
BioReco has not been used.

The plant has been running for 10 years, with the addition of BiosaHerb Environmental Microorganisms in the first 2 years. 10 liters / 100 m3 of lake water/year