ah...ok, read your thread wrong... 
I also think it wouldn't matter outside or inside of the chamber if the tubing is solid black and no light can reach inside. As long as the oxygen are used up before going into the chamber, it wouldn't matter where the tubing is placed.
Let see other's opinions!
_________
Started on Jan 24, cycled on Feb 17
125 gallons (72" x 18" x 22"), 20 gallons sump, 29 gallons fuge. 90 lbs sugar fine sand in MT and 30 in fuge.
Equipments:
Coralife Super Skimmer 220 w/ an air pump to increase micro bubbles, Mag drive 9.5 return pump
2 Maxi 900 and Rio+ 2100 as powerheads, Mag 350 filter
Lighting:
110watts PC, 70watts NO
Resident:
2 Polyps Ricordia
Royal Gramma, Lawnmower Blenny
Sally Light Foot
Pepermint Shrimp
70 Blue Leg Hermits
25 Snails | 
