Randy...I hope this is as appropriate a place as any to find you in order to seek your counsel...
I plan on running a top off line that uses a y connection to merge with an alk line terminating as close as possible to the point just before the output reaches the tank (will be going sumpless). The point of this is, even if prophylactically, to try to avoid clogging of the alk line at its terminus.
Anticipating that I may one day add mag to the top off reservoir, and having read your previous cautionary advice against combining mag and alk, I am thinking/hoping/wondering if the amounts might be so diminimis in this potential scenario and combined for so short a period of time (before reaching the tank at which point all would be immediately dissipate after coming into proximity of a powerhead) that this scheme would largely not be problematic. All pumping would be done via various independently run and timed Litermeters so volumes would be slowly delivered (if that is germane). Occasionally, I would anticipate both lines running simultaneously and other times completely separately. The maximum tubing length where the fluids might be combined would be approximately an inch and a half or so and the maximum length of time that small volume might remain combined before ultimately being ejected into the tank would be about ten minutes.
Apologies for the verbose question; I hope it is clear and makes sense.
As always, thanks for your advice, Doc.