FAQ – Frequently Asked Questions

Purification is done completely without chemicals, using reverse osmosis. Water is forced with high pressure through a semipermeable membrane to separate the impurities from the water. The holes in the membrane are so small (approx. 0.1 nm) that only water molecules can go through, thus leaving larger ions, molecules, viruses, bacteria, etc. on the other side of the membrane to be washed away with the feed-in flow.
The device is highly energy efficient and designed in such a way that anyone can perform the necessary maintenance. In regular use, the only required maintenance is changing the upstream filters once or twice per year (this can be done in less than ten minutes). If the device is stored in a cold environment during the winter, the device needs to be prepared by removing water and feeding antifreeze into the device. The device’s energy consumption is approximately 0.5 kWh per 100 liters, so if electricity costs are 0.12 €/kWh, the price of water is around 0.60 €/m³ (in comparison, tap water price in Finland is approximately 4.00 €/m³).
The device is designed for the conditions in Finland, the other Nordic countries, and Russia. The device can create potable water from almost any puddle. It should however be noted, that the salinity of the water to be purified must be under 0.8 % (the salinity of the northern Baltic Sea is usually around 0.5 %. Higher salinity requires much stronger pumps and internal pressure in the device). The device removes sodium, fluoride, arsenic, manganese, iron, uranium, sulfates, organic matter, medical residuals, bacteria, viruses, algaecides, fertilizers, etc., basically all suspended solids, soluble or insoluble. The device also removes small amounts of radon, but if radon concentration is very high, we recommend adding a larger active carbon filter or aeration device after the device. If the water contains large amounts of insoluble suspended solids (sand, oxidized iron, etc.) we recommend adding another sediment filter, for example 50 µm, to the device’s intake. Reference table for admissible concentrations for drinking water and the allowed maximum values for the device, so that the purified water meets the recommendations and the device remains free of substantial malfunctions:
DefinitionSTM 401/2001 maximum admissible concentrationMaximum for EMPRO (typical)
Escherichia coli<1 CFU/100 ml100 CFU/100 ml
Arsenic As10 µg/l500 µg/l
Fluoride F1,5 mg/l100 mg/l
Nitrate, NO350 mg/l2500 mg/l
Nitrate nitrogen, NO3-N11 mg/l500 mg/l
Nitrite, NO20,5 mg/l25 mg/l
Nitrite nitrogen, NO2-N0,15 mg/l7,5 mg/l
Uranium, U100 µg/l5000 µg/l
Coliform bacteria100 CFU/100 ml10000 CFU/100 ml
Ammonium, NH40,5 mg/l25 mg/l
Ammoniacal nitrogen, NH4-N0,4 mg/l20 mg/l
Chloride, Cl100 mg/l8000 mg/l
Manganese, Mn100 µg/l2000µg/l
Iron, Fe400 µg/l9000 µg/l
CODMn(O2) (chemical oxygen demand)5 mg/l15 mg/l
KMnO4 value (chemical oxygen demand)20 mg/l60 mg/l
Radon, Rn1000 Bq/l5000 Bq/l
Electrical conductivity2500 µS/cm (=250 mS/m)13000 µS/cm (=1300 mS/m)
Turbidity NTU (FTU)1ei oleellinen
Color5 mg/l PtNot applicable
pHNot applicable
Total hardnessmmol/lNot applicable
Calciummg/lNot applicable
Magnesiummg/lNot applicable
OdorNot applicable
AppearanceNot applicable
Alkalinitymmol/lNot applicable
Antifreeze liquid is fed into the device to prevent freezing. In the spring, the antifreeze is emptied from the device, after which it is once again ready for use. The antifreeze liquid is non-toxic and approved for food contact applications.
The device comes with a two year warranty, provided that the device has been used according to the warranty clauses. The warranty does not cover filters and other normal wear and tear.
The water produced by the device is extremely clean and soft. Two unrelated laboratories have analyzed water samples from the device using accredited methods. We are happy to provide the results of these tests on request.
The device is well-suited to also be operated on solar power. We also offer a solar panel bundle consisting of a solar panel (250 W), two batteries (250 Ah each), a controller, and an inverter. This is sufficient for regular use in a cottage during the summer months (water use approximately 200 liters per day). If water consumption is higher, the panel capacity must be expanded.
Yes. The device can be attached directly to a regular well pump.
The device is very quiet. With all pumps running, the device’s noise level is approximately 52–55 dBa which is similar to a quiet dish washing machine.
The maximum power consumption of the device is approximately 500 W, i.e. approximately 2A. The device is plugged into a regular grounded socket.
The device has a 200 liter buffer tank for the purified water. The tank has a float switch, which it uses to detect the water level. When the water level drops under a certain threshold, the device begins to produce more purified water into the tank automatically.
Yes. The difficulty of installation can be compared to installing a dish washer or a washing machine. However, we recommend that the required connections are performed by a licensed plumber so that the insurance companies’ conditions are met.
Normally, the only required maintenance is changing the upstream filters once or twice a year. If raw water is taken from the sea or a lake, the marine pump’s suction filter should also be cleaned every now and then. This depends on the quality and algae content of the raw water. If the device is stored in a cold space during winter, antifreeze liquid must be fed into the device and rinsed out in the spring. The typical lifespan of the membrane filter is approximately five years. All maintenance work is quick and easy to do yourself.
When empty, the device’s weight is approximately 40 kilograms, with the water tank filled the weight is approximately 250 kilograms.
The maximum lift height with a marine pump is approximately 20 meters. The longest implementation between the central unit and a marine pump is approximately 150 meters, but the distance itself is not a problem as such. As standard, we ship the marine pump with either 25 or 50 meter hose and cable.
We recommend leaving the device on, so that it performs a rinse cycle every 12 hours to rinse the dirty side of the membrane element with clean water. This significantly reduces bacterial growth on the membrane’s dirty side. The purified water does not contain bacteria, or nutrients for them, so the water inside the tank will not go bad. It is also constantly cleaned by the regular rinse cycle. If the device is left unpowered for a longer period, we recommend not drinking the water from the first tankful. It can of course be used as washing water, etc.
The device is a completely Finnish innovation. Certain parts are manufactured by us or subcontracted in Finland, some components come from Europe or the United States. The device has no Chinese or eastern components. Assembly and testing are performed in Hyvinkää, which is also where spare parts are available from. The device is developed and manufactured by EMP-Innovations Oy