Welcome to the club, you have come to the right place. I'm a bit of a novice here, but I can tell you that the GSF and BHC are typically an undesired fish to have in a pond. They reproduce more than most and eventually overpopulate the pond and their growth stunts due to too much competition for food.
I am very curious how you ended up with both in the pond. If it was from flooding high waters then it may be something you have to live with and manage the best you can. If not, and it was some fluke, like a neighbor kid sneaking in and stocking your pond for you then that would be a different matter. I am going to bet that most advise would be to kill the pond and start over with your desired species so long as the likelihood of getting the BHC and GSF back in the pond is minimal.
Otherwise, if you don't want to kill the pond, you should consider stocking some LMB along with the CNBG and CC along with removing as many of the BHC and GSF. These stocked fish should be large enough that your existing populations can't eat them. The LMB should help control the GSF, BHC, and CNBG recruitment. They are eating machines. A common thought for small ponds is that they are not easily managed for big LMB, so, you use the LMB to eat the young of that year (YOY) so that your populations don't get out of hand. You don't want the LMB to get so big that they eat your larger CNBG so you remove any that get over 13 inches or so.
Anyhow, food for thought. I struggled with the thought of my 1/4 acre pond getting overpopulated and decided to go a totally different route involving HBG, RES, and HSB...not near as much recruitment, but feeding becomes more important.
I am very interested in your green water concerns because I went something similar last year. It went away on it's own after a early summer rain flushed the pond.
