Dear Paul,
we are sorry to learn that you had a bad experience using DANSAND® NO GROW™. As we understand, you applied NO GROW in 2021. However, you do not specify which exact NO GROW product you were using. In the below answer, we will be assuming that you have used DANSAND® NO GROW™ Joint Filling Sand.
DANSAND® NO GROW™ Joint Filling Sand has been developed to prevent weeds, but it is not a weed killer. The product consists of washed and oven-dried silica sand, to which we have added a natural mineral. The mineral increases the pH-value and the ZAR value of the silica sand, creating an “unfriendly” environment that does not provide nourishment for weed plants. Hence, a weed seed that finds its way to your joint and tries to set roots here, will dry out after a short time.
We recommend a joint height of min. 4 cm when filling your joints to ensure that the roots of the seed do not have enough time to find nourishment, as it will dry out before then.
It is therefore important that you filled your joints in a height of 4 cm when you first applied DANSAND® NO GROW™ in 2021. Likewise, it is important that you have are maintaining your joints on a regular basis, making sure that they are always completely filled.
If you are interested in receiving our help to analyze further, we would ask you to go to our website www.dansand.dk and fill in our complaint form, which you will find here: https://dansand.dk/products/service/complaints/?lang=en