about recycling the tank and sump, i would suggest you putting air stone in the sump and the tank to speed up the cycling process, you probably can remove them after the tank has been fully cycled. I was trying to to cycle my 75 gallon with 20 gallon sump for 3 weeks without success. i measured ammonia almost daily and it range from 2-6. i had 1 of my ray in there so it forced me to do water change every other day. I had a korialia powerhead in the tank , just like you do and saw no improvement on the ammonia level in those 3 weeks period. After reading a couple of post some where about bacteria and oxygen. i added a large airstone to the sump and also put in a 2nd power in the tank with a air hose attached to produce micro bubble and alot of it. I immediately saw the ammonia level being reduced the next day and within 4 days, my ammonia level is 0.