What does the RHP-certification mean for substrates?

All cultivators want to get the most out of their crops and get a maximum yield.


In order to get this it all starts with a solid base, whether you’re a beginning or a more experienced grower. With this base we refer to the substrate you grow on. Choosing a substrate depends on your own preferences, but when do you know what kind of substrate works for you and how do you know if the substrate is of good quality? Learn about substrates and the quality of it in this blog.

At Atami we always make sure you grow on substrates of high quality, with our high quality standards we only deliver the best of the best. However, we cannot just claim our substrates are of high quality. So, in order to give you this certainty the Atami substrates are certified by the European knowledge centre for growing media, called RHP. Most of the Atami substrates have received the RHP certification, whether you grow on soil, hydro or coco based substrates.

RHP is since 1963 the European knowledge centre for substrates. The substrates that receive the RHP certification provide you the optimal start for your cultivation. The RHP certification ensures the grower that the substrate complies with the quality requirements concerning water uptake, air content, pH, EC value and nutrients added.

It also offers the security the substrate is clean, pure and that it can be used without any risks harming the cultivation. This is very important, because substrates without the RHP certification have the risk of being contaminated with heavy metals, radioactivity, seeds of weeds, insects, human and plant pathogens.


    Only phytosanitary clean raw materials are allowed to use in the production of the substrate in order to minimize the risks and exclude pest and diseases that could influence the cultivation. To prevent the contamination of the raw material we need to take hygienic measures when producing and transporting the substrate.

    As mentioned above, RHP also monitors the quality of the substrate in the production chain, from the raw materials used to processing them and delivering them to the end user. Organizations that produce RHP-certified substrates need to comply with several high standards. To give you an example, the origin and properties of the raw materials and the additives need to be registered for using in RHP-certified substrates. Apart form that, the EC value and pH level are being checked.

    When the RHP-certified substrates are produced they are constantly monitored on their performance by analysing and testing product samples according to a sample plan.

    After approval the substrate officially receives its certification, which you can recognize by the RHP logo on the bags. Have a look at your Atami substrate; the RHP logo is both on the front and the back!

    So, now you know how to recognize a high quality substrate and why Atami is very proud of our RHP-certified substrates. All you need to do know is choose whether you want to grow on soil, hydro or coco, but that depends on your preference! Let us help you out with choosing the right substrate and read our other blogs about the Atami substrates; you know the quality is great!