LFS said tank is ready for betta already?

I’ve been cycling my new tank for a week. A friend gave me her established sponge from her filter, seen at the back. I went in today to my local dish store to pick up some more plants and told the fish guy my parameters, he said it was ready for a betta. I feel like that’s too quick after cycling for just a week? 6.6gallon -Forza 45ghp filter filled with fluval bio max media from friend’s established tank -Free Sea 50w heater, temp in tank is 80 -Fluval Stratum for the plants -Lots of live plants -Mopani wood

Parameters for the last 3ish days have been: - Ammonia 0ppm - Nitrites 0ppm - Nitrates 20ppm - PH 6.4 Tested with API master test kit

Apologies for formatting, I’m on mobile