we have REALLY bad allergies here (asthema the works) and here is my 2 cents ..
AIR PURIFIER .. get WAY bigger then it should be and CLEAN weekly
tanks are fine just insure no alge issues (UV HOB filters help) and insure they are not allergic to the plants in the tank
CLOSE all chemicals TIGHT... prime has sulfer in it (I'm SERIOUSLY allergic to sulfer, so is my daughter), and most of the ferts make me sneeze.
cover the tanks (i don't) but i have an air filter NEXT to the tank (had to move it in there) as i'm allergic to all things green, furry, etc.. (and i have carpet so that means i'm always on allergy stuff)
my daughter actually ruled out going to some colleges due to allergins in the classrooms/dorms (sorry Princeton, stop emailing not happening) another thing that might be causing it could be the stand .. pressed wood is full of glue and stuff that is not great for allergies.
i use the air purifier from lowes and leave on HIGH every time she leaves the room, it's SO quite you can run it on medium when they are IN the room.
Oh, NO DIY CO2 (the smell is an issue for me, but as i'm the only one i suffer) i have college to pay for in the fall so a regulator system is out.
and a duh, NO (no matter how much the beg) fluffy, soft, teen, carpets ...
oh, and get a dyson - they REALLY do work if you have ANY carpet left - i do
we went through a 1.5 year on meds allergy cycle that we KICKED with LOTS AND LOTS of air purifiers ... we didn't run them during sandy and she got sick ASAP...
it's prob. not the tank...
ps.. love the willingness to tear up the carpet ... WISH we could.
i feel your pain... lots of Dr bills on this side, lots of things canceled, and i drive hotels crazy when we travel (allergy free rooms, or i bring my air purifier and run it for a few hours before i let her 'hang' in the room) ... i wish i could say it gets easier but it seems to get worse with stress and 'growth' stages.