6th Gen - antifreez problem

hi my 98 civic has a problem.
the antifreeze is decreasing I changed the radiator but still decreasing and I don't see any leak at all under the car or even around the hoses
please help.
I have no idea what to do nest
thank you

Did you bleed the system afterwards? If you don't, then while air bubbles are still making their way out of the system, it could appear that the coolant level is decreasing when really the air is escaping and making the coolant level lower.

Or you could be burning coolant. Do you notice any smoke coming from your exhaust?

there is more air I have no idea why the antifreeze is decreasing

I'm saying that it could appear to be decreasing, when in reality the air pockets escaping make the level of the liquid drop.

Look at it this way. Say you have a glass of milk. You take a straw, and you blow air into the bottom of the glass of milk. The air pockets that form make the surface of the milk rise, but as that air escapes to the top, the level of the liquid goes back down.