Nan I believe you're near to the sea and I would suggest you look at investing in a fibreglass pressure tank. I went through several of those cheap ones and eventually went for a more expensive fibreglass model which has a membrane inside. Came to about RD$ 50,000 but it won't rust and will be cheaper in the long run. I'd suggest you go to Almacenes Unidos in Bella Vista, they have a good selection of models imported from the US and the quality is good.
Buy cheap buy twice as they say.
Buy cheap buy twice as they say.