Seachem levels:
1.025
Ca 420
Kh 8.5
Mg 1300
Tunze:
1.025
Ca 430
Kh 9
Mg 1350
These are averages from the tests that I would take on new batch mixes. I like both, but I feel that I can use more test kits on the Tunze salt and get more accurate results. When I was using Seachem I never felt like my Elos or Salifert kits were testing correctly because they were always a little off from the Seachem test kits. Weird.
I switched from Instant Ocean to Tropic Marin about 3 months ago and I would never go back to IO. Im getting much better color and growth from all of my corals since i made the change.
The tropic marin is more expensive then IO. It usually runs for $90-$100 for a 200 gallon bucket. But as much money as I've spent on some of my corals I think its worth spending the extra 30-40 bucks especially if im getting better color and growth.
Where are you finding the Tropic Marin salt mix at? I've never seen it at the LFS before.
Cheers,
Alex