i just changed my goldfish water and the filter has stopped working . now the fish seems to be struggling to swim breath etc
for now, get a clean jug that has NO SOAP on it whatsoever, and lift a jug of water out of your tank and pour it back in such that you can see bubbles under the water. Periodically keep doing this... just do it in a manner that is not right on top of your fish.
If you have an air pump and airstone, perhaps consider using this as a bit of backup for now, this is mostly just to stop the water from being 'still'.
while doing this whip your filter out after first unplugging it and if you've your filter manual follow the guide in it for cleaning and check the impeller on it too.
If its like my fluval u2 which has this Venturi at the top, it seems to stop functioning if you submerge that too much. Soluton is move filter up a bit, or lower water a bit. I usually remove a bit of water as my water level is often taking into account some kind of air layer.
Check the obvious.. fuse in plug if it has a fuse.
What make and model is the filter?
If your filter after all has been tried is just totally whacked, then keep it submerged til you have a new filter and then if you can put the filter sponge or other media where possible into the new filter.
Hope you get this sorted.
The same thing has happened to me, but with my air pump, there is vibration but nothing is coming out of the filter do I need to clean the filter, or something, coz I'm worried about the fish and the fish tank is making a disgusting smell!
Some aquarium filters use a syphon to circulate water. If you remove very much water, the syphon tube will be full of air, not water. Just dip it in the aquarium to fill the U-shaped syphon tube and hold one end of it while you put it back in the filter.
To stop the buzz in an aquarium pump, add a bleed valve to relieve excess pressure. It will also make less noise if you put the pump on a foam pad.