Hi, some background to my fish: Male betta, have had him for 2 months, only done a 30% water change few weeks ago and that’s the only one I’ve ever done to clean his tank since I got him. However, yesterday I changed my tank water yesterday, put new gravel in and installed a new filter media. I done this because his tank was sooo dirty with algae and poo etc, it was staining the whole tank. For the water change: I kept about 25%-30% of his water (Wish I kept more because I added more gravel than last time so I needed more water). For the new gravel: I just added it how by rinsing it and I also mixed some of his old gravel and gravel water with it too so I could keep the good bacteria. And for the filter media: I just cleaned off his old one in his old water and then I put the new filter media in his old water older for a bit. However, now my fish just seems to be hiding and he will occasionally swim around and then just hide. He didn’t eat today either (but I fed him twice yesterday when I usually feed him once, he may not just be hungry but he’s still not doing much). I done a water test and all other levels are fine but nitrate and nitrite are through the roof ridiculous. Could you help me please? I’d really appreciate it! I’m new to this stuff :/