Two days ago I had an abundance of Brown mold in my FH tank. On glass and bottom. It’s a bare tank. No substrate or ornaments. I scrubbed and did a 50% WC . Yesterday morning FH looked fine no problems. I went out of town overnight and when I got home today he is very faded. Almost no red left on lower mandible and an almost yellow strip across the top of his mouth. Not eating and lethargic. I test water and 0 ppm on ammonia and nitrite. 5ppm on nitrate but my Ph is down to 6 ppm or lower as that’s as low as I can test. So I assume the ph has been down since I did WC which at this point has been 48 hrs. How damaging is this for the FH and how to I raise ph without shocking him.
