PH was low in the tank this morning. Typically that just means the Kalkwasser Topoff resevoir is empty. I refill it every 10-14 days.
That was not the case this time. Upon further investigation, the Spectrapure Dosing Pump LM3-MPM ( controlled by Apex aqua controller ) had failed. Pump has been online since Nov 2014. The peristaltic tubing had split combined with kalkwasser had made a mess in the head unit. Hopefully all that will be needed is to clean it up and get new tubing in there. I ordered 2 sets of replacement tubing from Spectrapure so that I have a backup. Worst case, a replacement head is $89. From now on, I plan to be proactive and change tubing out annually.
As a temporary backup, I replaced with a Tom's aqua lifter. It will work fine in the interim but will probably need to tweak the aqua controller timing to compensate for the difference in flow.
Prior to using the Spectrapure pump, I was using the BRS 50ml per minutes pump. I had two BRS pumps fail both around the 12-18 months mark because the plastic gears strip out. Having used Spectrapure litermeter for many years in the early 2000's, I opted for the Spectrapure basic pump instead of another BRS. Hopefully, nothing more serious with the pump and the switch to Spectrapure will have paid off.