How to Make Saltwater for Hermit Crabs... quick & easy
How to make saltwater for hermit crab in just 3 steps! It’s easy and quick. Saltwater is very important for your hermit crab’s health. In the wild, hermit crabs live on the ocean’s edge. Their life cycles rely on ocean water. There are over 70 trace elements in ocean water, including calcium, magnesium, zinc, sodium and many more. Make sure to use only saltwater mix made for hermit crabs or saltwater aquariums (do NOT use kitchen salt).
1. Start with pure water
Never use water directly from your faucets for hermit crabs. There will be chemicals like chlorine, chloramine, ammonia etc. that is very bad for hermit crabs.
Best water? RO- reverse osmosis. If you have RO water in your home, use it for your hermit crabs! But if you don’t, you’ll need to start with distilled water or water you’ve detoxified.
Detoxifying water is easy. Purchase a product made for saltwater aquariums or hermit crabs for this specific purpose. We use Amquel Plus, but there are other brands that are also good.
Don’t make saltwater for hermit crab pets without starting with distilled, detoxified, or RO water! Then you can add saltwater mix.
2. Add Saltwater Mix
Buy saltwater mix that is specifically made for hermit crabs OR saltwater aquariums. We use different kinds and rotate them periodically. Why? These mixes are all a little different and contain trace elements important for your hermit crabs like calcium, magnesium etc. – but they are all slightly different.
The measurements vary between different products. Most are one teaspoon of mix makes one cup of saltwater.
If you’re going to mix a full gallon of saltwater so you have extra to store for another day… you’d need 16 teaspoons.
16 cups = 1 gallon
3. Stir really well
Good salt mix will take a minute or so to stir and dissolve. Keep stirring until the water is completely clear and no salt mix is left on the bottom. Make extra and store it away from the sun (or it will start to turn green with algae growth).
The smaller the water dish, the more frequently you’ll need to change the water. Generally for hermit crabs, freshwater should be changed every day. Saltwater should be changed 1-2 times per week.
However, if you have a larger habitat and larger water bowls, consider adding an air stone and/or mini filter. This is possible with water dishes that are 1.5″ deep or more. By adding an air stone and/or a mini filter, you can usually extend the life of that water by another day or two. It’s aerated and won’t get stale as quickly. But watch for hermit crab poop and food or dirt that they may drag in! If there’s debris, you’ll need to change the water right away.
Providing saltwater at all times helps to keep hermit crabs healthy. You’ll see, they like to spend time submerging in both freshwater and saltwater.
A note about freshwater: because we use distilled, RO or detoxified water, it doesn’t contain beneficial trace elements that they need. This means the saltwater that DOES have the important trace elements is that much more important! This also means you should always keep a mineral block and/or cuttle bone inside the habitat. See more about cuttle bone for hermit crabs here.
Looking for more information on best water dish options? See Hermit Crab Water Dish Options for Smaller Habitats and Hermit Crab Ramp Ideas here.
Last update on 2025-04-23 / Affiliate links / Images from Amazon Product Advertising API