Canister filter throwing air bubbles into DT
 

I have a Eheim canister filter for my 55gal tank. Lately once in awhile it will make a sound like it does when it first starts up and then throws a ton of micro bubbles into my DT. More so after my water change last night and I didn't even take the thing apart to clean it. ( I do that every other week) Can these filters become air locked? or is it drawing air from some where?
Also my return for my skimmer is above my intake for the filter, would it be drawing in air bubbles from that possibly and then blowing them back into my tank?
Sorry for all the questions. I just don't want to take the filter apart if I don't have to.

Wow it has been a long time since I used to have a filter and had that problem.
I think that rather than correcting the problem you might want to consider removing the filter which is a nitrate factory.
I take it you have both live rock and live sand to aid in filtration.

I have about 65lbs of live rock and about 2" sand bed. I'm pretty strict about my cleaning routine and I haven't had any nitrates since my tank was still cycling, so I'm not worried about that at this point yet but I do know that they are known for that. Thanks for the input.

with my ehiem on freshwater have had to bleed the air out every time i start it up again

I'm guessing that it is pulling in air from the return on your skimmer. Once it builds up to a certain point in the filter it will release out the return. You could try switching the intake and return lines on the filter to see if this fixes the problem.

I have ran canister filters on SW tanks in the past with ZERO nitrate issues. However, I always jam my tanks with liverock and usually use liverock rubble in the filters instead of the bio media.

Hope this helps.

I think I fixed it, I tinkered with the skimmer a bit and now no more micro bubbles. It was sucking up bubbles from the return line of the skimmer.
Thanks