HP Instant Ink - When to Change Cartridges?

[larrymcj1]

I'm currently still using the starter cartridges that came with my Tango printer, but several weeks ago I received my first set of cartridges from HP Instant Ink. The trick-color cartridges has been reporting "low ink" for a couple of weeks and the black cartridge is at about 25%. 

1. When should I replace the tri-color cartridge? Now or when it's visibly closer to empty? 

2. Should I replace the black cartridge at the same time or wait until it reports "low-ink"

Theoretically, for a printer that has a trick-color cartridge and a black cartridge, if I printed primarily with black, does HP Instant Ink recognize this and in the future send me only black cartridge replacements? Or will they also send the trip-color even if it happens to be well over half full?

In general, HP needs to post some guidance about when to replace cartridges in this program. Using "best practices" is not always the best advice. I don't want to waste ink, nor do I want to ever run out.

[Valsimot]

In the user manual on page 50 is explained that ink levels is an estimate and the ink should be replaced when print quality is unacceptable and on page 52 details about Instant ink plan.

[larrymcj1]

While I appreciate your reply, it does not answer my question at all, nor does page 50 or 52 in the Tango owners manual address my question.

I'll ask again...HP Instant Ink sent my first set of replacement cartridges earlier than needed and now the trip-color cartridges display "low ink". The black cartridges does not. Do I replace the tri-color cartridge now or wait until the print quality is decreased? And do I replace both cartridges at the same time, even if only one cartridge is low on ink?

I don't want to waste ink or abuse the Instant Ink program, but HP does not make these things clear anywhere.