Dishwasher rinse aid

What formulation and concentration should I choose for my rinse aid?

The first thing to check, especially in the case of professional dishwashers, is water hardness. This hardness is measured in degrees Th.
You should therefore first check the hardness of the water that supplies your dishwasher.
A water softener will significantly lower water hardness and prevent limescale stains and deposits on your dishes. It's also worth noting that limescale builds up more strongly when the temperature in a dishwasher is high.
The presence of softened water guarantees better results and lower product consumption.
If you do not have softened water, you will need to pay attention to the range of use of the rinse aid and choose a product for hard water or all water.

Foam phenomenon linked to over-concentration of rinsing?

Foam sometimes appears when the dishwasher comes out, especially in the tub.
This foam may be the result of using too much rinse aid , but be careful not to systematically blame the product.
In fact, in most cases, if the dishes are pre-washed manually using a shower or in a bath with a hand-held dishwashing product, it is the latter, if not rinsed properly, which can cause this foam.
A manual dishwasher product generates a lot of foam and this poor rinsing leaving traces of products will have a multiplier effect in the dishwasher.

Is the rinse aid the only guarantee of results?

In any case, the rinse aid, like the washing product, is only one element of the result.
A poorly maintained dishwasher with dirty rinse arms, clogged rinse nozzles reducing pressure, an unsuitable water temperature, etc. are all parameters that will be as important, if not more so, than the product itself.

In conclusion, the product is certainly important but will never guarantee a result on its own, just as it will never be the sole cause of a poor result.

Why do my dishes come out of the dishwasher white and dull?

No, it doesn't necessarily come from the rinse aid or even the detergent. First, check the hardness (TH) of your wash water (before using products that have a sequestering effect on limescale). If your TH is higher than 8 or even 15 or more, your water is too hard and, added to the water temperature, the latter will deposit on your dishes . This forms a film that will make proper washing more and more difficult.
Solution: Check the setting of your water softener and then descale your dishes and dishwasher.

I have a lot of foam in my dishwasher wash tub?

Two possibilities: either you have too high a dosage of rinse aid , or you pre-wash with a hand dishwashing product that has not been rinsed enough and it is the "leftovers" and traces of surfactant from the product which, once in the tank, create this foam.
Solution: Reduce the rinse dosage and check that the dishes are properly rinsed during hand pre-washing.