Fishtank help
I'm new to fish keeping and am not really sure what I'm doing, nothing on TikTok is really helping me, I've got a hot water tank with guppies dwarf gourami and neon tetras, I have shrimps/snails too. I do weekly water changes about 20/30 percent and make sure the water is treated first. I have had 3 fish die since getting the fish (4 months ago) and I'm not sure what I am doing wrong. I want to do a full water change as the rocks I have put in my tank seem to hold a lot of dirt when I water change the dirt comes back up not sure if that's what's causing these problems, some say full water change is fine others say not, I've got bad snails too as well as assassin snails to kill them but it's working very very slowly and hoping a full tank clean out I can get most of the bad snails out, any other help would be appreciated