Aquaforest probiotic method

[Myka]

Originally Posted by spedly

I have a Vertex refractometer and ensure it's calibrated before every measurement. Do they have a limited lifespan? This one is about two years old.

You calibrate it every time before you use it? That's a bit excessive. If you're just using it on one or two tanks, and it's not traveling around anywhere getting bumped around or exposed to significant temperature changes, then once every 2-3 months should be sufficient. How are you calibrating?