Where to find a good light bulb?
I've got a heavily planted 10g with demanding water hyacinths, water wisteria, dwarf hairgrass and something else I can't remember, one of the very common, dark green, broad-leafed plants. Populated with rasboras and a dwarf gourami. The only bulb I can find that fits my hood is 15W and I'd ideally like to have 20-30W. The necessary bulb size is 18in; can anyone tell me where to find a good full-spectrum 18in bulb?
Alternatively, I'd take instructions on building a DIY hood and a recommendation for a good bulb that would fit the project.