How to Add Salt and Rinse Aid to a Dishwasher and Set the Water Hardness

Foggy glasses, water spots on cutlery and a white limescale film inside the tub are usually not a detergent problem: the dishwasher's water hardness level is set wrong, or the salt and rinse aid have run out.

According to manufacturer instruction manuals, if your tap water is harder than 7 °dH (roughly 12.5 French degrees) the appliance's decalcification system has to be active, and that system only works if there is special salt in the reservoir and the level matches your water.

This guide shows how to find your water hardness, how to change the level from the appliance menu, and how to fill the salt reservoir and the rinse aid dispenser in the right order. The first run takes about half an hour; later salt top-ups take a couple of minutes.

1. Find out your tap water hardness The first line in every manufacturer's procedure is the same: ask your local water supplier for the hardness of your tap water. On the website of your city's water and sewerage administration (in Turkey: İSKİ, ASKİ, İZSU, SASKİ, İSU and similar), open "Water Analysis Reports" or "Subscriber Services → Analysis Reports" and look for the "hardness" row in the report for your district. Turkish reports normally use French hardness, printed as "°F" or "°fH". Not every utility publishes this parameter; if you cannot find it, call the utility's customer line or measure it yourself with a hardness test strip from a supermarket.
2. Convert the value into the unit your appliance uses Water utilities use French hardness, while appliance manuals usually print their table in German degrees (°dH) and mmol/l. The conversion is simple: 1 °dH equals about 1.79 °fH, so divide the French value by 1.79 to get German degrees. One °fH corresponds to 10 milligrams of calcium carbonate per litre (10 ppm). Example: 25 °fH in the report is roughly 14 °dH.
3. Read your level from the hardness table in the manual The number of levels differs per brand, so always take the level from your own manual. The table in Arçelik's manual has six levels: level 0 for 0-8 °dF (0-4 °dH), level 1 for 9-13 °dF (5-7 °dH), level 2 for 14-22 °dF (8-12 °dH), level 3 for 23-27 °dF (13-15 °dH), level 4 for 28-34 °dF (16-19 °dH) and level 5 for 35-90 °dF (20-50 °dH). On Bosch's higher-end models the same table is split into eight steps labelled H00-H07, while some entry models only have four levels shown by the number of lit indicators. The factory setting is normally chosen for medium hardness, so if your water is very soft or very hard the setting is wrong from day one.
4. Enter the settings menu and change the level With the appliance empty and no programme running, open the door and press the on/off button. On Bosch models with a display you hold the info (Setup) button for 3 seconds to enter the settings menu, press the forward button until "water hardness" appears, set the value with + and -, then hold the info button for 3 seconds again to save. On Arçelik you enter the menu by holding the settings button for 3 seconds, or by holding on/off together with the P2 programme button for 3 seconds; P2 steps to the "r" line, P3 selects the level (r:1, r:2 and so on), and holding on/off for 3 seconds exits. Button names vary by model, so check the "setting the water softening system" section of your manual.
5. Locate the salt reservoir and fill it with water on first use Pull out the lower basket. The salt reservoir is the large screw-capped compartment in the floor of the tub, right next to the filter; do not confuse it with the rinse aid dispenser, which is inside the door. Turn the cap anticlockwise and remove it. If you are commissioning the appliance for the first time, fill the reservoir right up with water first. This is only needed for the very first fill, never for later top-ups.
6. Add the salt, tighten the cap and wipe up the overflow Fit the funnel and pour coarse-grained dishwasher salt in up to the top of the reservoir; never use table salt or salt tablets. Salty water overflowing from the reservoir into the tub while you fill is completely normal, so do not worry about it. Put the cap back and close it tightly (a loose cap causes both excessive salt consumption and deposits inside the tub), then wipe up the spilled brine. Never put detergent or cleaner into the salt reservoir; the manual states plainly that detergent destroys the water softening system.
7. Start a programme immediately after adding salt The rule the manuals underline: always add salt just before starting the appliance. That way the overflowing brine is flushed away during the first wash and no corrosion starts in the tub. Loading salt and then leaving the machine idle for days can leave marks, especially on a stainless steel interior. If you have a full load ready, run it; otherwise a short programme is enough.
8. Fill the rinse aid dispenser The rinse aid dispenser sits on the inner face of the door, next to the detergent compartment. Press the catch on its lid, lift it, and fill with rinse aid up to the "max" mark inside. Use only rinse aid made for domestic dishwashers. Close the lid until it audibly clicks into place and wipe away any spilled rinse aid with a cloth, otherwise the next wash will foam excessively.
9. Set the rinse aid level The rinse aid dose is a separate setting, usually adjustable from 0 to 6. The Bosch manual recommends level 5 for very good drying results, and its troubleshooting section points to the 4-5 range when glasses show marks. You change it in the same menu as the water hardness: step to the "rinse aid" line and use + and -. Only touch this level if the result is wrong: lower it if glasses have a removable streaky film, raise it if dried water droplet spots remain.
10. Check the result after the first wash and fine-tune Run a normal load and hold the glasses up to the light. White, stubborn deposits in the tub or on the dishes mean the decalcification level is still too low for your water, so raise it by one step. A bluish film on glasses that wipes off with a finger means too much rinse aid, so lower that level by one. Once you have the right combination, the only remaining job is refilling the reservoirs whenever the salt and rinse aid indicators light up on the panel.

⚠ This guide is general information. Yudum cannot be held responsible for the outcome of following it; for official procedures always rely on the institution's own statement. Steps and fees change over time.

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