Hi,
I think that you just need to recalculate the volume of your CH for the new volume of the tank.
The bottom line is this: Your existing CH is designed to handle some volume of alcohol vapor from your 500 liter (gallon) tank.
At the same time, this volume of filling CH can only process the volume of alcohol that comes out of the tank of 500 liters(gallon).
Now you have a tank of 2500. This means that you need to put proportionally more material in the CH (proportional to the amount of alcohol vapors, alcohol) than for a 500 tank.
But there is one big problem here: the rate of release of substances from the material that you put in the CH will be different. You can ignore this, and just make the CH proportionally larger in volume, anyway, then you will be engaged in changing the concentration of alcohol (adding water, proofing alcohol).
The second important thing: your new CH should not create a lot of resistance to alcohol vapors, so you need to maintain (proportionally) the cross section of the vapor passage compared to the old one.