Automatic water softener „Aquaphor“ S550 with iron and manganese removal

„Aquaphor“ S550 — automatic water softener with 15 L of resin that also removes iron and manganese

A cabinet softener that treats all the water supplied to a home or small business, with a nominal flow rate of 1,380 L/h, metered regeneration and a salt tank that holds up to 25 kg.

The „Aquaphor“ S550 (manufacturer code 515763) is a water softener made by the Estonian company AQUAPHOR International OÜ, with the resin tank and the salt tank in a single cabinet. Its fine-mesh monodisperse ion-exchange resin removes the calcium and magnesium ions that make water hard, as well as dissolved iron and manganese. The controller uses readings from the built-in flow meter to work out how much water can still be softened and starts a brine regeneration at the preset time.

According to „Aquaphor“, the tank design and fine resin beads mean regeneration needs up to 30% less salt than a conventional column softener, and the resin lasts up to ten times longer than in a typical softener. The control valve is the patented „Dual Core“ design with a built-in bypass valve, which lets you isolate the softener while untreated water keeps flowing.

Feed water requirements

The softener is designed for mains or well water. „Aquaphor“ sets these limits for the feed water:

Hardness, iron and manganese together, expressed as CaCO₃ (the compensated hardness), must not exceed 1,200 mg/L, which is 120 °fH (French degrees) or about 67 °dH (German degrees). Within these limits, „Aquaphor“ specifies treated water with no more than 0.3 mg/L of iron and 0.1 mg/L of manganese.

The softener does not remove colloidal iron or organically bound iron (typical of brownish ‘peaty’ water). Sand, ferric iron and other undissolved particles must be stopped by a pre-filter upstream, and water with a pH below 6 needs a pH correction filter.

Compensated hardness and regeneration modes

To know when regeneration is due, the controller needs the compensated hardness in mg/L of CaCO₃. Multiply the hardness in mg-eq/L by 50, multiply the sum of iron and manganese (mg/L) by 85 and add the two figures. For example, with a hardness of 6.84 mg-eq/L, 3 mg/L of iron and 1 mg/L of manganese: 6.84 × 50 + (3 + 1) × 85 = 682 mg/L. If your hardness is given in degrees, 1 °fH equals 10 mg/L and 1 °dH about 17.8 mg/L of CaCO₃.

The salt used per regeneration depends on the selected mode:

* Our calculation, not an „Aquaphor“ figure: capacity divided by the compensated hardness in the example above.

• AU — the controller tracks daily water use and sets the amount of salt accordingly.
• HC — a fixed salt setting with less frequent regeneration.
• HE — a fixed salt setting that treats less water between regenerations but uses considerably less salt.
• 96h — regenerates at least every 3–4 days, even when little water has been used. It must be switched on when the water contains iron or manganese, so that the iron it removes does not precipitate inside the softener.
• Enhanced iron wash — regenerates every other day using 1.6 kg of salt each time. Run it for at least two weeks; „Aquaphor“ recommends doing so at least once a year.

Regeneration takes 30–40 minutes: backwash, brine draw and slow rinse, second backwash and refilling the salt tank with water. Do not run dishwashers, washing machines or other water-using appliances during regeneration, so schedule it for a time when no water is drawn, usually at night. The display shows how many litres remain until the next regeneration, and the flow indicator helps you spot leaks.

„Aquaphor“ S550 and S800 compared

Installation

• Install the softener in accordance with local plumbing regulations; „Aquaphor“ recommends having it fitted by its service department or a regional dealer.
• Install it after the pressure tank and pump controls but before the water heater and other appliances. The pipe feeding the softener must have a bore of at least 3/4″.
• The softener has 1″ NPT male connections. Connect it with the supplied 1″ × 3/4″ flexible hoses and their seals, without PTFE tape or sealant. Do not reverse the flow: the direction is marked by an arrow on the bypass valve.
• Supply pressure must be 1.4–7 bar; at least 2 bar is recommended for reliable brine draw during regeneration. The supply must deliver at least 9 L/min. Sustained flows above 30 L/min may reduce treatment efficiency.
• The room must stay at +5 °C or above, with relative humidity no higher than 70%. Keep the softener at least 1 m from heaters; installing it on underfloor heating is not recommended. An unswitched socket must be within 2 m; the softener runs on a 12 V AC adapter from a 220 V supply. Do not put the softener alone on an uninterruptible power supply (UPS): „Aquaphor“ allows this only together with the pump set, as otherwise regeneration can fail.
• Regeneration water leaves through the supplied 16 mm (5/8″) drain hose, which must not be reduced or kinked. The drain hose can be run up to 1.5 m above the softener's drain outlet, provided the supply pressure is at least 2.75 bar. The salt tank overflow needs a separate gravity line with a bore of at least 12 mm (1/2″), falling all the way to a drain at least 8 cm below the overflow fitting; never raise or kink it. Never join the drain and overflow lines (for example with a tee), and leave an air gap of at least 5 cm between the end of each line and the highest water level in the drain.
• An external bypass with shut-off valves is recommended: it makes servicing easier and keeps water flowing while the softener is removed. If the pipe from the softener to the water heater is shorter than 3 m, a non-return valve is recommended on it, as close to the heater as possible.
• At commissioning, pour 8 L of water into the salt tank and start a regeneration manually. Only then add salt and run about 270 L of water (about 20 minutes) through the softener.

Salt and maintenance

• The salt tank holds up to 25 kg of purified tablet or granular softener salt (NaCl). Do not mix types of salt or use rock salt. Always keep the salt above the water level and topped up to at least a third of a full load.
• If the salt runs out, top it up and wait at least two hours for a saturated brine to form before starting a regeneration.
• If the water contains iron, use an ion-exchange resin cleaner every six months and run the enhanced iron wash at least once a year.
• Check and clean the salt tank and air check valve once a year. To disinfect the softener, make sure there is water in the salt tank, pour 120 mL of 5.25% sodium hypochlorite solution (household bleach) into the brine well and start a manual regeneration.
• Protect the softener and the drain line from frost.

In the box: the softener, controller, overflow fitting, 2.5 m drain hose (16 mm ID), two 1″ × 3/4″ flexible hoses with seals, 12 V AC power adapter, 1/2″ drain pipe and an instruction manual.

The S550 P1 version has a KDF85 layer for hydrogen sulphide removal instead of quartzite. This listing is for the standard S550 (515763) with quartzite.

Specifications