It is possible to have Zeolite media in these kind of reactors. The key is to have enough flow and space inside the reactors so that the stones can be properly shaken up.
A Phosban 150 may not be enough space for 1.2 liters of Zeolight media. You may end up needing two of those.
You can use a slightly larger pump for flushing the media. For example, if you are running a 200gph pump to circulate water through the reactor, you can use a 300gph pump as the flush pump. Adding air will help clean the media even better.