Do i need a uv?

[cichlidcichlid]

I have a 90 gallon pond and i have not gotten the filter or equiptment yet. If i were to just have a spong filter with some plants and fish would it still get a big algae bloom? Should i have a uv? Do they work?

If i got one it would be like this:

http://www.petsmart.com/product/index.jsp?productId=2750628&cp=&pg=1&searchSort=TRUE&sr=1&origkw=uv&kw=uv&s=A-StorePrice-PET&parentPage=search&keepsr=1

If the link doesn't work go to petsmart and type in uv and it is the one built in with the power head and spong.

Would a spong filter work though?

I Would love not to get it if i don't have to but i want cyrstal clear water.

Internal UV Sterilizer with Power Head and UV Sterilizer Lamp Replacements

[hankn]

UV is just one part of the equation to achieve clear water. The other 2 parts are plants in the water (they compete with the algae for nutrients) and shade. Any one of the 3 missing and you will have partial green water.