in a previous job i worked for a granite & marble company. alot of our product was imported from china. we would order tiles, kitchen & vanity benchtops & even all the parts for the britomart railway station & paedestrian crossing parts for the refurbishment of the streets around the railway station in Auckland. Once you find a good supplier of what ever you are after you were set. I found that the quality was effected by the value you wanted to pay. ie: If you wanted a teaspoon it would cost $1. If you wanted a teaspoon for 5c you could, you would just get 5c worth of quality.
I have a sunsun tank, i have had it for around two years & cannot fault it at all. It is better IMO tha the aquaone AR980 that it is similar to & I would recommend them. Just make sure you are happy with the one you buy beforeyou hand over the $ as there are less quality tems out there.