I want to build a low cost carbon scrubber for my stealth grow Box (Any Ideas ???)

I want to build a low cost carbon filter/scrubber for my stealth grow Box (Any Ideas ???)
My setup is very similar it this one in terms of size & style . Picture's would be greatly appreciated thanks for reading .

click on the link below DIY micro scubber
hope it helps

thanks guys !!!
https://www.rollitup.org/members/budmasterflash-320813.html https://www.rollitup.org/members/budmasterflash-320813.html