As I am sure many of you have already realised I am in the process of renovating and upgrading an existing pond. I am not do sure if the existing and new pipe couplings are going to take the pressure of the water flow once the pump is installed so I am thinking of using collar clamps wherever a coipling and pipe meet. However, some of these joins are underwater. Is there a rust resitant collar clamp available ? Plastic clamps just dont seem strong enough so I guess metal clamps are the only option. Would coating these clamps in Silicon/Waterproof paint be an option (in order to avoid rusting)?.