Hey guys, I'm super worried about my betta. Just to give a bit of a background, he's been in a cycled 2.5 gallon tank for 4 months with no substrate. Recently I bought some new black quartz sand as well as anubias, Christmas moss and Amazon frogbit. 3 days ago, the betta started becoming less active and I thought he was just stressed out from being in a new environment. However he got worse (clamped fins and pale) and I noticed the amazon frogbit were turning brown and the Anubias were melting. Thinking that they were probably contributing to an ammonia spike, I removed them immediately and did a tank flush with Prime. Currently the tank only has the black sand and the Christmas moss, but my betta doesn't seem to be getting any better. In fact he may be getting worse, he did not even move when I went near his tank today. What could be wrong? Could my sand/Christmas moss contain some organic matter that is decomposing? Will removing the sand help? And what can I do to help my betta make out of this alive in the meantime? I have an unused 1 gallon tank, should I transfer him over?