Yes air stones. Okay I will check back after I test. I'm currently at work so I won't be home for another half hour to do it.With doing that to the UGF filter media, you may have lost a lot of the BB. Same for scrubbing the surfaces inside. You need that liquid test kit to monitor ammonia and nitrite levels as the BB re-establishes. What is the driving force for the UGF...air stones? I wouldn't personally keep one fancy in a 10 gal tank...20 long minimum. And I would have a secondary HOB on it along with the UGF and preferably drive the UGF as a RUGF with a small powerhead for such a messy fish.