No, didn't add anything to it and never had it apart until last month. It had stopped working about a month ago so i took it apart and cleaned it. When initially opened it up the o ring was lying in the bore. I didn't know where it belonged so i put it on the very end of the impeller assembly cap below the magnet. It stopped working again yesterday and when i opened it up there was the o ring again, lying in the bore, not where i had left it. This time i noticed that there is a small gap between the magnet and the end cap of the impeller assembly. I rolled the o ring over the end cap and seated it in that gap. Seemed to fit in there just right so thats where it's staying for now. Its running. Maybe its a spare part that was accidently left behind in manufacturing?
Wish i had another SeaFlo kit. I'd get another maxi-jet and hook it up. The seaflo kit on the maxi-jet blows away the stock koralia in terms of flow. Thanks to whoever donated the seaflo kit to one of LIRAs raffles.