sub mf-800 filter help please

[laura77]

i have got a mozoo filter mf-800
(2nd hand)

can anyone tell me what the clear tube that has a little black plastic thing on the end is??

does it alter the flow ?? (doesnt seem to) and is it an in the water part or out of the water part??? sorry never used one and the instructions are missing from the box..

also is a filter ever TOO big for a tank??

its just ive put this one in my small tank 50L and there seems to be quite a current. ive put it in my small tank because soon im going to be putting it in a 3 foot 250L tank and i want it to mature a bit fist

 

[CARL7]

Just joined and saw yr post. I just got one of those filters. The hose is to be attached to the filter's top, and the black part left outside is for air suction, it then pumped into the water. Its "air intake Diffuser". Providing additional needed Oxygen for tank inhabitants...