if i had been fighting it this long, and didn't want to seed with media from the 2.5, i would do the following:
1) empty the tank (no plants, no gravel, no nothing)
2) fill with dechlorinated tap water
3) keep pH in the 6.5-7.5 range
4) keep temp around 80*
5) add ammonia to 4ppm at the same time of day, every day.
6) do a partial water change if the nitrates get above 60-80, and bring them back down to 20-ish or lower.
7) after cycle is complete (ammonia and nitrite both to zero every day after adding up to 4ppm ammonia the day before), add gravel back in and test daily for a week and see if there are changes.
8) if no changes, add plants back.
9) if no changes after a week, stock the tank.
10) remember, this WHOLE time continue to add PURE ammonia back up to 4ppm every day, until you add the livestock (in #9).
this whole process should take no longer than 30 days, the cycle should not stall, etc.
1) empty the tank (no plants, no gravel, no nothing)
2) fill with dechlorinated tap water
3) keep pH in the 6.5-7.5 range
4) keep temp around 80*
5) add ammonia to 4ppm at the same time of day, every day.
6) do a partial water change if the nitrates get above 60-80, and bring them back down to 20-ish or lower.
7) after cycle is complete (ammonia and nitrite both to zero every day after adding up to 4ppm ammonia the day before), add gravel back in and test daily for a week and see if there are changes.
8) if no changes, add plants back.
9) if no changes after a week, stock the tank.
10) remember, this WHOLE time continue to add PURE ammonia back up to 4ppm every day, until you add the livestock (in #9).
this whole process should take no longer than 30 days, the cycle should not stall, etc.