Which is the better t8 light Arcadia or Hagen. My tank hold 4 15 inch tubes. My old tank I mixed An original and a freshwater Arcadia tube but never tried Hagen. My tank is going to have a few easy to grow plants and is a 125 ltr
You can use pretty much whatever you want. You aren't limited to specialist aquarium tubes.
In my humble opionion I get the best colouration and brightest greens from combining a pinker tube like specialist plant tubes ( I use Sylvania Grolux) along with a whiter standard daylight tube.
But it really depends on if you can't source them and if they work out cheaper, lampspecs for example do not stock a suitable quality 14W T8 daylight tube probably because it is a less usual size.