i would like a koralia 3 for my tank but they are expensive here in the uk, is there anything similar and works well but not as expensive ? i see very cheap 'wave makers' on ebay from china are these any good or is there even any other brands of circulating pumps that are cheaper than the koralia ? 
also it must be quiet i dont want to buy something cheaper and noisy

also it must be quiet i dont want to buy something cheaper and noisy