hmm, you can get the bulb from most hardware shops that carries light bulbs. i changed the bulb for my freshwater one too. both are phillip 11W. costs around 4.50 each. regarding water splashing, i fill water until the part where water flows out so that i wont get any on the inner sides. but my bulb still has salt particles due to evaporation. i guess this tank just not suited for saltwater. a saltwater aquarium needs to be covered.