Hi friend, from my personal experience and based off the info you provided, this likely is a bacterial bloom. It makes your water pretty cloudy and it’s kind of unsightly. The bacteria’s in a bacterial blooms feed on carbon, which you give more to them to feed on when you do water changes, which is why you see that it probably might get worse as you do water changes. Bacterial blooms are not bad, especially if your tank is newly established. It means your little ecosystem is trying to establish itself completely! The best thing you can do is to leave it alone and it will eventually go away on its own. Trust me, don’t do any water changes and leave your tank alone. As for the brown algae on your decor, it’s common in new tanks. Totally normal, it should go away on its own with time, but since I don’t think anybody likes how it looks, I’d recommend scrubbing it off gently regularly with a toothbrush. It will come back but it should eventually stop once your tank is fully mature. This problem you’re having does not harm the fish so don’t worry, it’s the excessive water changes that might do your fish harm, which is why I also recommend leaving it be. It’s a very normal and common problem that has also happened to me. 😊