Ok, understood. If you want to deal with the high Nitrate , you’ll need to take ownership of this issue. If I sold you an established tank 11 months ago and it has high nitrate as the only problem , then the problem is on you to resolve.
Let’s start with the basics:
Tank size and age
Stocking list
Water parameters
Equipments in tank (lights, filtration, etc)
Cloudy water could be the result of precipitation or a bacterial bloom.
Only way you are going to get through this is take ownership and formulated a plan of action
If nitrate is leeching from your rocks, take them out and cure it. You’ll need patience as you’ll need to test it along the way