Just mixed up some IO, Ca not so good

[mark]

Started another pail of IO and low numbers with this one as well.

Made up 20g ro/di then left for a day with a couple of small pumps to aerate, added 12 cups of IO and then left mixing for another day.

Tested today and have:
SG: 1.025 refractometer
Ca: 270 Salifert and 300 twice with ELOS at 71°, thought maybe sample temp so warmed to 78° and got 275 ELOS.
Mg: 900 ELOS
Alk:10.9dKH Salifert
pH: 7.8 using pH monitor and after replacing battery and recalibrating probe.

Either I'm doing something wrong or IO is.

[Aquattro]

Originally Posted by mark

Either I'm doing something wrong or IO is.

IO has always mixed that way for me for the last 8 years. Ca always low 300's, alk around 10 -11.