Upgrading Aqua Ultraviolet 25w to 57w

[ConsummatePro]

I have been using the same 57 watt Aqua Ultaviolet ballast for 8 years and never had a problem. I don't know why you were advised against using them.

I did find some threads saying the AquaUV ballasts burning out but I just assumed the Pentair supply would allow me to choose either the 25 or 57W option.

 

[alabella1]

What about the opposite direction. I got a 57w unit local from someone not realizing it was too much for my 155g tank. Possible to just swap the 57w bulb for a 25w or do I need a downgraded transformer as well?