Update:
To echo some advice from Greg(oldude), check your alk and calcium parameters at least every week or so, and check your equipment for issues. I did some tests last night with the following results:
Ca: 400
Mg: 1290
Alk: 8.3
NO3: Between 5 and 10
PO4: 0.01
When I had the snafu a few days back with the pellet reactor not pulling in water the Nitrates had risen to over 10, and the phosphates had come up a bit too. Its the first time in about a year I have had measurable Phosphate. That slowed down the use of the Alkalinity, which rose to about 8.6. So Nitrate and Alkalinity are dropping as expected.
However, the last time I checked Calcium it was at 460 and Magnesium was at 1400. I checked over the equipment and it turned out my calcium dosing pump was turned off in the Apex interface. Its probably been 3 days like that, but I don't remember turning it off, in fact I don't usually turn them from Auto to off at all. I have an alarm programmed if they are left on, but not for them being off(a lot harder to do that).
The Salifert Amino acids ran out about a week ago. Starting a few days later, the cyano began disappearing. Its almost entirely gone now, from both tanks. The Flubber tank always has had some on the sand, but its pretty clean right now. Ill probably go back to to Acropower - its easier to get and delicious as well!