Adding candy sugar.. too late ?

I am doing a belgian dubbel. Is it ok if I added my candy sugar (about 500g, in sirup form) after the fermentation had stopped. It has been about 5 days since i've pitched. Initial plan was to add it 48-72 hours after pitching.. but I was too busy.

BTW now that I added the sugar fermentation have restarted (a lot of popping in the air lock). I plan on waiting another 1-2 days then transfer to carboy for 1 week.

What do you think?

Its fine. Many people that brew BIG beers slowly add fermentables or the yeast to slowly consume so they are not overwhelmed at the being of the fermentation process. Just watch your sanitation.

Thanks Bradley.

What do you think it's the impact on taste of adding it tardily ?

The effects on flavor should be no different than adding it in the boil.

It's fine.

How long should I wait in the second stage (carboy)?