Update on this: I gone back to using Mrs. Wages pickling lime to create a solution for a top off kalk solution. I am however still using the magnesium supplement. I'm very happy with the growth I'm getting and will continue to use it. In case anyone is interested, I'm using a more diluted solution than is usually prescribed online. I lose 5 gals. every 2-3 days so I drip from a 5 gal ozark container using regular clear tubing with a knot to control drip. I mix only 3 tps. into a 5 gal container and I'm very happy with the results now.