Just a quick update, most of you should be receiving your root tabs tomorrow. Hopefully the letter carriers did not obliterate them in the handling process. I wanted to also add that you should treat these just like you would any other root tabs. I personally add them at the base of any large rooted plants I have in the tank, and at the center of any large groupings of smaller plants.
I think the general root tab recommendation is 1 per sq foot to around 18 sq inches of area, and make sure they are buried deep.
These tabs do have macronutrient KNO3 in them so a nitrate spike is possible, but not likely if they are buried in the substrate.
Thanks again and hope to hear back soon.