<a href=showthread.php?s=&postid=13304802#post13304802 target=_blank>Originally posted</a> by was16803
The evaporation depends on a lot of parameters including how tight your hood/top or open top, temperature, humidity, etc. The amount of make up needed may be perfectly normal like the others have said. If it continues, however, I would check for a small leak or even some "wicking" path. These can occur where hoses, power cords, returns, Hang on filters, pumps are located at. I good indication is excessive salt creep