water/lime mixture? lime is poorly soluble in water, that could be a problem... If using a wet tek (i.e. an acqueous solution containing the alkaloid/plant/base mix), you have to use another base such as lye. lime should only be used for dry teks (where the plant material is dry-mixed with the lime and only very small amount of water is added to make a paste).
another possibility is that you used too much naphtha and that the plant has very little alkaloids, so the naphtha might not have been saturated enough and when putting in the freezer, it didnt crash out. Next time maybe use significantly less naphtha, mix it for longer and maybe also pre-evap before freezing. Or try evaporating instead of freezing and seeing what youre left with
yet another possibility (related to the last one mentioned because it would eventually mean less alks in the naphta) is that just doing one acidic soak and filtering is not very effective in taking out a significant amount of the alkaloids, that boiling the acidic solution with the plant material and straining, and adding more acidic solution and straining again, for a total of 3x, and only then basing it, would get more alkaloids.
another possibility is that there isnt any (or very very little) dmt in your phalaris in the first place.