So I found a scientific study where they bred figure 8 puffers, as well as several other puffer species. I'll link to the article if anyone is interested. The only issue I that, when they reported on what salinity they used, they expressed it in percentages. The salinity at which the puffers bred was apparently 9%. The salinity they started at was 30%. My guess is that they're talking about the percentage of seawater salinity, so 9% would equal 35ppt * .09, or 3.15ppt, which would be 1.0024 specific gravity, and 30% would equal 10.5 ppt, or 1.0079 specific gravity. Since the latter is pretty close to 1.007, the upper limit of salinity recommended for figure 8 puffer keeping, I think I'm right, but I'd like the opinion of the internet hive mind. What does "a salinity of 9%" mean?