Had a fully functional water feature with filtration set for sale. Goes with top view ranchu and and a very rare beautiful butterfly goldfish. Pond set bought from nursary and it cost me a bomb, now selling at a fraction only. The filter is biological and it breaks down the waste and you hardly need to change the water. I am a fish keeper and i design the internal filter myself as most of the water feature or ponds you buy from the nursary do not have this filtration function.