If you were to look at factors that cause pool water to turn green or cloudy, having a damaged and/or improperly maintained Pool Filter (Or a Cartridge Filter) is going to be at, or near, number one. The pool's filter type has a number of factors that influence whether or not your pools water will be clean, clear, sparkling … or cloudy, murky, green, yellow, brown ... Each filter type has its own list of reasons as to why it will allow the pool water to go green or murky. Please look under:

"New Pool or Equipment Replacement Recommendations" - "Filters" (Click HERE!)and examine the information under your filter type.