The Fluval AquaClear 50 filter? It'll be alright for the 37g. Remember that more filtration is almost always better, and you may be able to get the FAC 70 online for the same price as the FAC 50 in the store if you're willing to wait. If you also buy the heater online, the shipping might be free. and one great thing about these filters is the fluval sponge filter intake covers at the store for $3 fit nicely onto the intake tube
I don't mind getting wet!it does have a center brace at the top but it seems real flimsy.
Yeah, those center straps are designed to work in tension, so they look kind of thin and flimsy. Without it, the 37 would really bow out in the center once filled to the top.