Going Saltwater: A Guide to Converting Mollies and Guppies To Saltwater

If you’re an experienced freshwater fish keeper, you may be looking to expand your horizons and explore the world of saltwater aquariums. But what about your beloved guppies and mollies? 

Can these common freshwater species successfully transition to a saltwater tank? The answer is yes, but it requires careful planning and preparation. In this blog post, we’ll explore the process of transitioning guppies and mollies into a saltwater tank, including the necessary steps to ensure their health and well-being in their new environment. 

Whether you’re a seasoned aquarium hobbyist or a curious beginner, read on to learn more about this exciting and rewarding endeavor.

I have always been fascinated by saltwater tanks especially tanks that have coral in them but I am too much of a chick to take the step to get a saltwater tank. I am not very good at being precise in dosing so I feel like I would kill my fish or corals by being off on the salinity. I have recently seen that you can buy pre-mixed salt water at PetSmart so it takes away the risk of that.

But many people don’t realize that some very popular fish can be converted to saltwater. Most of them are fish that come from brackish water but some that you would never think of are guppies and mollies.

It was super surprising to me that they could be transitioned to saltwater but the more I think of it they are such hardy fish that it shouldn’t have been.

To convert guppies and mollies to saltwater you will need to acclimate them to saltwater. It is often done over a few weeks of doing lots of small water changes on the tank for 2-3 weeks tell the salinity in the tank is the same as the tank you will be introducing them to.

The one problem with doing the acclimating process over a few weeks is that every time you change the salinity level it will cause the fish to stress and stress is the number one cause of death and sickness in fish. 

The most common way to transition guppies and mollies is to do it over a 7-12 hour period of time. This makes it so all the stress of acclimating to the new salinity happens at once and causes fewer problems. 

You can do it one of two ways. The first is every 10–15 mins you add a small portion of water to the container or tank the guppies entail the salinity is the same as the tank they will be transferred to.

The other is to drip acclimate them. You use tubing from the new tank to the container with the guppies and/or mollies and transfer the water. You will want to restrict the flow so that only a few drops come out at a time. Once the salinity matches your tank then you can introduce your tank.

Another thing you will want to monitor is the temperature of the water. When acclimating fish you will want to make sure the temperature stays within the right parameters. I have made this mistake a few times. I come back and the water is ice cold and the fish died from the temperature drop.  

Since then I have always used a container that is big enough for an aquarium heater so I don’t freeze my fish to death.

One concern many people have is if guppies’ and mollie’s life cycles are the same in saltwater and for the most part, they are.

Guppies and mollies can grow, breed, and have babies in a saltwater aquarium. Which is amazing. Most animals if the living conditions are off slightly won’t breed or are stunted in growth. So you know that they are healthy.

Also mollies tend to grow much bigger in saltwater than in freshwater. I have heard cases of them reaching 6 inches in length.

While guppies and mollies can transition into saltwater most fish can’t. Sometimes people get confused that certain can be transitioned to saltwater because some illnesses in fish can be treated with aquarium salt. So please do your research on fish that you put into a saltwater tank. For example please don’t try to transition betta fish or goldfish into a saltwater tank because it will kill them.

In conclusion, transitioning guppies and mollies into a saltwater tank can be a challenging but rewarding experience for fish owners. It requires careful planning, research, and patience to ensure the success of the transition. By gradually acclimating the fish to the new environment and providing them with the appropriate water parameters and diet, they can thrive in a saltwater tank.

Overall, transitioning guppies and mollies into a saltwater tank can be a unique and exciting way to explore the diversity of the aquarium hobby. With proper care and attention, these fish can adapt and flourish in their new environment, providing a beautiful and vibrant addition to any saltwater tank.