Lid on a Saltwater Tank

The lid should not negatively effect the ph value unless it blocks out the light. A tight fitting lid is great for most all species of fairy wrasse and other nervous fish. The lid can also help with evaporation and could help you not have to top off as often. If you have a fish you are worried about jumping out then I would get a lid, glass tops are the best as they don’t limit the light. Note: make sure to keep glass lids clean as salt creep can diminish your light and can impact the intensity in reef tanks.