Here are info about Water
Puffers live in all three water types: fresh water, brackish water and salt water. Some puffers can live in all three types of water. Some only could tolerate one type and some two types of water.
Puffers are a warm water fish and likes a high ph. Here is averages for Temperature and ph. I recommend to you if you have a rare puffer look at the "Kinds of puffers/Species" page for their temperature and ph.