I love this tank, although as you say, getting the top part disassembled is a right pain, hence me only really taking the PMMA off, washing it out and reassembling, without touching the top section.
Another bugbear is the cost to get an SS/glass tank section is extremely expensive.
A big thank you for letting me know the bottom airflow controller can come off and I'm now getting the airy draw that I prefer, cheers mate, yet another great review.