I think I did the exact wrong thing, using epsom salts for mg. Probably didn't need to- and overdoing it could be harmful? I finally got a GH/KH test kit. My general hardness is 10, which I think means there's enough mg and ca in the water supply already- I should have figured as much, since I always have hard water residue on things. So what I had guessed was mg deficiency is probably a symptom of something else. This applies to my other tank as well. It's more likely I need to add calcium (the snail shells look eroded on their ends). Not sure. Well, the big wc I have to do this week after dosing meds will take out the extra mg I hope. Then I can figure it out.
The kH reading was 5- I read a bunch of articles and posts about gH and kH but still don't really understand what these numbers mean for my tank.