i use via aqua oceanpure pro salt.... its cheaper than other brands
ive tested it when mixing it at 1.025 SG and with my RO/DI water the calcium was 460 the alk was at 9dkh no phosphates or any nitrates and such
I use oceanonic in my reef tank and instant ocean in my fish only agrasave tank. the corals started doing beter after I switched out the instant ocean with the oceanonic . I do a 5gal weekly change in my 29 and a 10 gal change in my 75 every week.