Had the same problem, solution: make sure that the end of the hoses are cut absolute straight! Because of you don't, that's the place on the connectors side were it sucks in the air.

Beautiful plants but these are actually limnophila hippuroides. P.Stellatus doesn't have the serrated leaf edges

I talked to the oase turkey and they sent me a new one. I m still in shock how amazing customer care is this. I congratulate to oase for such a beautiful customer care. 😊😊👏👏👏

The same problem. This filter is a pice of crap, don't buy it.

do you know how to fix the air problem now ? thank u

Same problem with me in bradnew oase biomaster 850 on every startup have do airout it's making rattling noise

GUYS I JUST FINALLY FOUND THE SOLUTION! it is the counter pressure from the filter! just take the prefilter foams away and make them urself out of a less dense foam like the blue filter foams that came with the filter. this solved my air problem right away!

I had the same problem with the the oase biomaster thermo 600 and they replaced the primer unit that sits on top of prefilter, now I bought a 850 thermo and after 2 weeks still has aer inside, every day I shake the filter and still has aer inside ill contact them to see what they say about it.

That is an amazing planted tank. Nagyon jo 👌😂

Szia zsolt két napja vettem es nekem is Ezt csinalja.... räjöttél hogy mi a baj?

I never post anything but I just found out why my oase 600 was doing this, I have a bubble wall and the filter was sucking up the air, I know it's simple but something that people would not think of checking first maybe this might help someone with there pump

Solution can be simple. The cut on the intake or outlet hoses must be perfectly straight. No croocked or angled cuts or the screw will not shut airtight.

Try an inline valve to reduce the flow some. Impeller is most likely cavitating like a boat prop.

I have a brand new eheim 4+ 350 doing the same thing. It was actually sucking in the oxygen bubbles from the plants. I’ve now placed a foam sponge over the intake and has solved the problem. The foam sponge happens to be an oase orange one they use in the pre filter of oase filters.

(@Szakacs Zsolt, @Dennild, @MOLOKO ) I have the same problem. I want to test the hypothesis with the pre-filter suction tube (45166) so I removed this tube and filter sponge altogether. Left only the prefilter flask empty. Let's see what happens ... (I'll write the result in a couple of days.)

Good evening. Please excuse me, I don't speak English very well. i live in germany and have / had the same problem. i have already contacted oase, we are still in the process of clarification. What I found in advance and what helped a lot was first of all, attach and tighten clamps on both sides of the hose. and i have a bubble machine in the aquarium (at the other end of the aquarium) so far away from the suction system. I turned that off and it really got a lot better. but unfortunately not completely gone. let's see what I can do with oase.

I HAVE SAME ISSUE!!!!!!!!! ALREADY TWO MOUTHS!!! I can't sleep becouse of this. I spend so much money for this pise of sh*t. I can't sleep becouse of that. It starts vibrating at night becouse of air....... I'am so tired of trying fixing it. Someone find any solution?

Same problem, going to contact customer support. At least it still holds water

same here with a brand new 850T. Pretty annoying for a filter this price :(

Anche io ho riscontrato rilascio periodico di bolle d'aria con il mio oase 850

Same problem on mine. 850. Collecting a lot of waste in the system that's not going into the pre filter. Can't work it out. Nightmares

Mine does the same thing. But mine is loud and annoying