Heat pumps, solar systems and related issues

Hello
We are a family company from Slovakia, dealing mainly supplies heat pumps, solar systems and related issues. Currently, we handle the following problem for the customer:
Drilling wells for hlbek 15m and yield of 2 l / s is used as a heat source for heat pump water / water and also as a source of drinking water for the house. During drilling, we stumbled upon called. sands. The pipe was installed Honeywell F74C filter with 100 micron sieve with Automatic flushing and for the filter with 1