co2 is injected directly into intake of an Eheim 350 with Up Atomizer and periodically (every 5-8 minutes) throughout the day it spits out large bubbles. Do you guys think I need to replace atomizer? Does it have something to do with filter itself? I tried playing around with filter media (adding and removing some) yet it still spits out large bubbles, don't know what to do and worried that CO2 dissolve rate is very poor. Please help guys.