[MissBec]

I tested in a bucket and it work, the brand of the filter is hopar canister external. I change one pipe since it was really nasty and I put the two tubes into my tank and it's not doing anything at all!!!

It has in and out outlet and I tried sucking both of the tubes but it didn't start, it's second hand which came with my tank. I position the filter onto the floor and the tank is sitting on my desk it about 120 litres...

I notice there is few parts missing e.g. Spray bar, strainer and few pipes

 

[jaysee]

There is only one moving part on a filter and that's the impeller. Sounds like something is obstructing it. Have you cleaned out the motor?

 

[RSVBiffer]

As Jaysee said the impeller or possibly air in the system preventing a syphon.

 

[MissBec]

Yes I clean the motor it seems the impeller was out of place, it seem that the tube is having trouble sucking the water in , what should I do!

 

[jaysee]

I would manually fill the filter with water and then put the filter head on.

 

[RSVBiffer]

If Jaysee's suggestion doesn't work then I would disconnect the filter-in pipe from the filter and, with the Otha end still in the tank, suck on it until it starts syphoning. This depends if you have Taos etc on the pipe otherwise it can get very messy if you aren't quick :-D. Is there a priming button on the filter?