New here with lots of questions,

To start with I had no idea a pond could be so much to worry about. We purchased a place 3 years ago in Northwest Alabama that has a 3 acre pond that was built in 2013. Was told it was stocked with LMB,BG,RES and GC.
When we moved in we went to local Tractor Supply picked up fish feed and started feeding. The next spring I learned about FERTILIZERS. My local co-op had Pond Perfect so I started that and was successful in getting a green pond with no problems. Last year in late spring (May I think) I started fertilizing again. Two weeks in nothing. So added more. A couple of days later our pond looked like a pool. It was aqua blue. Not green it was between sky blue and blue bird blue. Don’t think we lost any fish or we didn’t see any. After 3 or 4 days the pond turned crystal clear. We got County Extension guy to check water. I showed him pictures of our blue pond and he said he had never seen that before but had heard of it once from someone at Auburn university. His test recommended 5 tons lime per acre. May of this year the lime was added but I am scared to add fertilizer. I did for 2 years but now I have submerged algae in different spots to depth of about 6 to 7 ‘. When I showed him a sample of it he said it was Chara and recommended Diquat. Another agent said he didn’t think it was Chara but Diquat would kill whatever it was. Needless to say I am very hesitant to put anything in the pond now. As the summer has heated up the algae is dying and coming to the surface in small clumps, not a lot just a baseball size clump here and there. I do plan on adding some more GC (10 maybe). I would rather try that then the chemicals if needed.
The things I think I have done right is liming and this year changed feed to Optimal BG. They seem to really like it. I am hand feeding from the pier.
Would aeration help my pond? Shallows are 2 to 5 ft and the deepest 18ft. The pond is shaped kinda like a peanut.
As y’all can tell I am wanting to do something to help the pond along but really don’t know where to go from here. Any advice or suggestions would be greatly appreciated.