in short i would say that your LFS is giving you bad advice (or at least dated advice). I would try to forget everything they told you and start learning from scratch 
The absolute best resource for building aquapod that I have found is this thread:
http://www.nano-reef.com/forums/index.php?showtopic=54602&hl=stealhealr&st=0
It won't have every detail you need, but covers all your major areas of concern and will give you a good start point for additional research..
just remember to take everything slowly.. you will realize that there is more than enough to work on in the tank without rushing things.. i could probably work on my 12g as a full-time job if i had the time
so rushing things can only cause problems which cause much more work for you..
The absolute best resource for building aquapod that I have found is this thread:
http://www.nano-reef.com/forums/index.php?showtopic=54602&hl=stealhealr&st=0
It won't have every detail you need, but covers all your major areas of concern and will give you a good start point for additional research..
just remember to take everything slowly.. you will realize that there is more than enough to work on in the tank without rushing things.. i could probably work on my 12g as a full-time job if i had the time