[2wheelsx2]

The only other one I does regularly is potassium sulphate. My fishload seems to produce enough phosphates (probably from the food). One that you may consider is CaCl as you usually can only buy it in bulk. If you have that and want to divvy out, I would be into some, as it probably dissolves better than plaster of paris.

 

[2wheelsx2]

Just my opinion, but I wouldn't bother with doing this with Mg, as epsom salts are available at every drug store or grocery store in 2 to 5 lb bags (even Costco) cheaply. It's the other stuff that is hard(er) to get in small quantities.

 

[2wheelsx2]

They won't make you sign anything if you buy 5 lbs at a time, multiple times.