what do i need to attach carbon filter to fan?

how do i connect a carbon filter to a 4 inch vortex fan?

I have the 6" version and this big ass carbon filter. I called HTG supply where I got it and they said to use the big hose clamps. I used 2 of them but still could not get the filter to stay on tight - the metal used in the fan and filter is much to strong for those clamps. I ended up just supporting it in place on my first grow. I am considering using a couple of screws to hold them together better this time.

almost seems like you need a huge muffler clamp to hold them together.

sorry for not having a good answer for you. Hopefully someone has a good suggestion.

thanks anyway gotta figure something out