Coolant level alarm kit fitted

Hi All,
Earlier this week I fitted B & G’s CL alarm kit. It’s working perfectly I.e. the self test does its thing every ignition and I tested the float before I piped the tank up.
In the original tank the coolant level was up the ridge about halfway up the tank. Now the level is as per the photo.
I need to add that at the same time as the CL kit was fitted I replaced the radiator bleed screw and lost about an egg cup full of coolant. When changing the tanks I siphoned out the original coolant into a 1 litre bottle that over flowed a little. I then put the coolant back in from the bottle. So, if anything the coolant level should be slightly lower. My first thought is there’s some air got in and if so it’ll need bleeding. Your thoughts on this would be helpful.
The temperature gauge is as it has always been and I’ve probably done about 10-15 miles since.
Cheers,
Michael.

The level on mine took a while to settle down after i removed the tank to fit the coolant sensor even though i had kept the hose propped up to minimise any coolant loss/ ingress of air. The level dropped twice after driving though not to the extent of setting off the alarm but it settled after that and has not needed topping up at all since.