i recently got a brand new canister filter to help take care of my messy flowerhorns. they are a breeding pair of blue lohans in a 50gal (M-10in, F-4in) they have been doing fine in the tank, but make alot of mess. so i ordered a new 100gal magnum canister filter to replace the previous 40gal wet/dry trickle filter (which has been running for 6months). i replaced the factory media with the biorings from the old trickle filter to keep the BB and hooked up the magnum. no new water was used. things have been good for the past 2 days (however, due to the strength of the filter/spraybar, a mass of bubbles is forming on the surface of the water). woke up todays and noticed that both FH were laying on the bottom of the tank, disoriented, and gasping!!! water parameter are the same as before (actually the nitrite is .005 now, lower then before) asked a friend what could be wrong, as i was stumped...he said it sounded like "GBD" gas bubble disease...can anyone give me any info on this? in not so technical terms? (looked it up online and couldn't figure out what they were talking about, sounded like "the bends" or something) i moved the spray bar under water to minimize the bubbles, changed 25% of the water...but i don't know what else to do. could i be overfiltering or aeriating? please help.
