A friend of mine has a 150 Gallon Preformed pond that is very green and you can not see to the bottom or her fish. She is using a planting basket(set on the bottom of pond) to set her 200 GPH Fountain Pump in with quilt batting and that just isn't working. She would love to add a waterfall on the edge but I can not think of how she could make one or if they sell small ones for preformed ponds? She has NO rock on the bottom of her pond as she took it all out last year. She does have a few water lily's but no other plants. Do you think she needs a bigger pump?? Would love to help her out but I have never had green water issues. Thanks in advance. Amber