The Puffer Forum

Soph<3GSP wrote:Hi guys and girls! (wasn't sure which topic to post this on, so sorry if it's on the wrong one!)

I was told by API to use their freshwater test kits for low end brackish tanks, but I was wondering when to use the saltwater test kits. Does anyone know if there is a specific gravity they should be used at? I was thinking about when it comes to upping the salinity in my tank, at which SG should I change to saltwater testing kits?

Thanks in advance for any feedback!

Tbh the difference in results is slight, so I'd stick with freshwater kit until 1.010-15 sg. Any higher might skew results some. Definitely saltwater for sg 1.018 and higher

Awesome, thanks!

I would not use FW kits above ~ 1.012, which is approximately the top of the change-over band between FW and SW bacteria, and also approximately mix-range BW. But in reality, there is no sharp dividing line.