<a href=showthread.php?s=&postid=11762930#post11762930 target=_blank>Originally posted</a> by Billybeau1
Salifert, Elos and API top my list. All accurate but Salifert gives a more precise result.
API is inexpensive but give general accurate results. 7 dkh, 8, dkh 9 dkh etc. Calcium = 380 ppm, 400 ppm, 420 ppm, etc
This doesn't matter to some folks.