Anyone want to offer thoughts on my use of silicone airline tubing for my dosing lines? I've had this setup for almost a year and set a reminder to check how they're holding up - all seem fine. I'm pushing Alk, Ca, Mg and NoPoX through them. Just come to calibrate my Apex Dos which I use for auto water change, on that I use the supplied Neptune tubing - its been in place the same length of time as the silicone dose lines but is now stiff and brittle! There must be a reason silicone tubing isn't the default for dose pumps?