Green water algae needs ammonia to multiply and thrive, and when the filter catches up to the load, then like magic, the green water will disappear almost overnight. As was mentioned, it may have been the precipitate from the calcium chloride addition that coated filter material, setting it back. It could be from the pond being somewhat new. It could be from feeding before the filters come out of the winter slump. It could be from the filters being under sized for the fish and feeding load. If it is from the precipitate coating the filter material, then taking the filter apart and cleaning it with some of the pond water will fix the problem fairly quickly. If it is just load on immature filter, then it will get there in time. If it is a case of the filter being too small then it will never get there without additional filtration. You have to remember that the fish grow and as they grow in length, they also grow in width and height, so mass is exponential, and filters that worked yesterday may not work tomorrow.
Zone 7 A/B
Keep your words sweet. You never know when you may have to eat them.
Richard