Generally speaking, it is, but you need to pay attention to the choice of the proper product. In fact, there are Ventury injectors featuring an adjustment device regulating the quantity of the suctioned solution and other “steady” ones, which do not enable this kind of regulation. There are models enabling to adjust the quantity of the suctioned chemical more or less accurately. You always have to take into account that the quantity of the suctioned chemical is always based on the flow rate of the water running through the Venturi injector. Therefore, on equal regulation, the quantity of the suctioned chemical will vary in function of the variation of the water flow rate, yet maintaining the same percentage.