Red Sea Fish Pharm Ltd. - Reef Salt 200 Gal (Store Use). Red Sea Salt is designed to provide the exact parameters of tropical reef water with a slightly elevated alkalinity as needed in a closed marine system. Red Sea Salt is ideal for fish and invertebrate systems or for low-nutrient tanks where you are routinely supplementing all of the individual elements on a regular basis. Store Use. Aquarium: Marine Salt 200 Gal Ship Dim: 18. 4x144. 3 in Ship Wt: 55. 8 lb