Aqualight Pro 150W ->250W

[Captainhemo]

I have a single 150W MH Aqualight Pro that I'd like to upgrade to 250W. Can I just simply purchase a new ballast such as the PFO 250W HQI and a 250W bulb? Are the sockets different ? What about the connection from the lamp to the ballast ? Trying to decide if it's even worth doing this or if its just easier to go with an entire new setup and then sell the 150W Aqualight P.
Has anyone done this or know what will be involved in it ?