Uncontrolled experiments--the fish pond

The fish pond was quite cloudy, and getting smelly.  To solve the problem, here's what happened:

• Half the water got pumped out. (It was used it to water the nearby plants) 
• That water was replaced with new water treated with a chemical said to turn tap water fish-friendly
• Two little "bale-ettes" of barley straw (said to clear pond water) were sunk below the pond surface.
• A heaping teaspoon of beneficial bacteria (bought at a pond store) was thrown into the filter
• The pond was "shocked" by pouring in ten different places, ten (total) capfuls of a liquid from a bottle claiming to be pond clarifier (motto: "fish love it")
• The pump was reconfigured to allow more water to run through the UV (algae-killing) light on one portion of the pump
• Water plants were added, the thinking being that these would remove nutrients from the water for their own growth purposes. Added were: 2 plants of golden moneywort (Lysimachia nummularia "Aurea") and three plants of water buttercup (I think this one is Ranunculus flabellaris).  (Truthfully, these were both chosen on the grounds of being the cheapest water plants in the water-plant house at Flower Factory, rather than because I knew anything about their special fitness for my purposes.)

Result? Clear water, sure enough, although somewhat green-or golden-colored from--I'm guessing--the barley straw, as all the other additives were clear.

The problem? Which of these step(s) caused the improvement?

Must all of these steps be repeated when the pond becomes cloudy again? This would be unfortunate, given that cloudiness occurs pretty much every time it rains--seems the spore for algae are washed out of the air to multiply like mad in the pond.  So, I'm left to guess and intuit which of these treatments had the most power.

The combined treatments were effective, yes.  Yet this is not a very scientific method of proceeding, is it?