is it ok to completely seal the opti spark so water does not get into it and short it out any help would be good thanks

What do you mean 'seal it'? Like with a type of silicone around the edges?

yes with silicone

Just don't over-do it, or let it come in contact with anything electrical. But I doubt that it will help a lot with moisture. When your opti goes out, look into the Del Teq solution.