I recently did four. At the same time and same sample.
Triton
Fauna Marin
Tropic Marin
Ati
Triton came back the quickest. 5 days
Fauna Marin and tropic Marin were oddly similar and came back the same time 8 days
Ati took the longest 10 days
Here is the spreadsheet I made up of results.
The blanks are either it wasn’t tested for it or I forgot to put a zero. Moving forward I think I’ll be going with ati. I tested against my Hanna phosphate, alk, and nitrate. Also against my salifert magnesium and calcium. These were the closest and it also gives supplements and dosage based on your water volume. The salinity’s however, were all over the place. lol. Gotta get that one figured out.