At the moment in my tank I have a Superfish retro LED and the Aqua one light fitting with 2 x t8 30w tubes. I will eventually upgrade to full led but for now I’m trying to work out what the cheapest option is. i Have no idea how old the tubes in the fitting are and could do with being replaced. If I do just replace them can I use standard white tubes or do they have to be aquarium tubes. What values would i need to look out for as far as lumen, Kelvin rating etc. The fitting has a clear Perspex covering and rests on a glass tray above the tank so no fears of water getting into the unit.