I recommend that approx 3 wraps around the barb filter fitting and not over tighten them - use a wrench but hold your hand close to the barb so you can not put alot of leverage on it as it is only plastic. Make sure that your index marks are correct - see page 1 of this tutorial - without filter installed. Use the vacuum resistant hose that came with the AIO - Alot of times while pulling wine thru a filter you will get CO2 being released - this is normal because it is under vacuum pulling thru an orifice (filter). If you are pulling a bit of air - don't be alarmed - You can not add that much oxygen in that short of a time frame. Just think how long a gravity racking would normally take ? Well you can transfer and filter in approx 4 minutes for a 6 gallon carboy.