So I bought an MP 40 from a user here and just tried installing it in my tank to start mixing water right in there (tank is bare) - and the MP 40 is not staying attached to the glass. This is IM 170, the glass is 19mm. This is supposed to work, right? I am not using any spacers. Any ideas what's up? I did a search and it seems to be some people have had this issue historically, but never clear what the solution was besides not using MP 40.


