Well not 100% certain. Back in June or so, I added 25 lb of boric acid to the 10,000 gal pool according to pool math. That would have given me around 50 ppm. For weeks afterwards it would read around 75 by the strips. But my salt levels were declining due to leaks and such (most of that saga is documented in various posts here), however my borate number never came down with the salt like I thought it should. I never added any more borates. I sort of just stopped testing borates after that. Recently I just tested again and this is what I got. So it could be anywhere between 0 and 100 lol. Maybe the strips are just bad?