Not related to your question, but table salt does not affect any of the parameters you're trying to control here. You should probably change up the GH
boster too. Epsom salt does raise both hardness and pH, but I think fish that need hard water are going to have a need for calcium, and right now your GH
is nearly all magnesium. I'm not completely sure that matters, but I would definitely research it a little. You can get calcium carbonate cheaply online, and it will raise GH
/pH all together, so you could have less sodium sulfate in the final mixture.
I should note that I know nothing whatsoever about Malawi cichlids, but I do know about chemistry. If you want these fish to have salty water in addition to hard and alkaline, your mix is fine, but generally for freshwater fish I'd go a little lighter on the salt.