Adding Inhibitor to a sealed system

[Skavenger]

Hello

I have a sealed Combi Boiler Central Heating System and have removed a Radiator for decorating. The system contains Sentinal X100 Inhibitor. When I removed the Radiator I emptied it out, now when I re-fit the radiator and re-fill the radiator I will be introducing fresh water diluting the system.
The heating system and inhibitor was fitted in 2001, when emptying the radiator the water was cloudy but very clean no sludge or rust.

Should I:

A. Not worry as the ammount of dilution would be minimal.

B. Try to add a small ammount of the same type of inhibitor if so how do I do this, put it into the radiator? The system is sealed no header tank.

Many thanks

 

[Softus]

You could test the concentration with one of these test kits..

And if you need to add any X100, you could do it like this.

 

[Skavenger]

Many thanks!