Magnesium def., recommend some nutes please?

I have determined that my plants have a magnesium deficiency. The ower leaves brown/yellow and curn at the tips and smaller lower leaves just wilt and die outright. The top of the plant is pretty healthy, though. Could someone recommend a good plant food with magnesium for me?

My plants are in crappy soil, too, but it's too late to fix. I started them in miracle grow (I didn't know any better at the time) then transplanted them into plain topsoil with 30% perlite. I now have a big back of FF ocean forrest but am going to hold on to it until my next grow, which will be clones of these ones in a week.

Currently my plants get 150ppm of a 5-1-1 organic fish fertiziler once a week and they should probably be moved in to bigger pots soon. They're growing under CFL.

Any tips helpful!

Water them with with epsom salt at 1tbsp per gallon. Also foiliar feeding them with this mix helps. I recently picked up a bottle of magnesium sulfate pellots that I sprinkled on the top of my soil to help with high magnesium demand from our plants. Dark green veins, with yellowing of the outer edges of the leaves.

you can also look at calmag or magical