Saltwater to freshwater

Question
About 2 years ago my family got a 55 gallon tank with the idea to start a salt water tank. My dad knew the guy who owned the salt water fish shop about 20 minutes from our house. Well we had many water problems.. The fish all died and the aquarium now sits in out basement on the fixed side built into the wall. I have decided to convert it to freshwater. Today I began adding some water to get the hardened salt and rocks out. I then removed rocks and gravel filled the tank about half way. And syphened it all out. I wanted to dilute the rest of the salt and remove it. I want to add fish like guppies and good fish to go with them like mollys. Well what should i do from here. Is the salt still a big problem?

Answer
Hi Eric

Well pretty much the only thing you can use when converting a saltwater tank to a freshwater tank is the tank itself. Filter, gravel and decorations would all have to be replaced. I've had many people, including a couple of experts on our site tell me they've used the same filter but always had problems with their new freshwater fish. So, I never recommend reusing the same ones.

The best way to clean the salt out of the tank is with a diluted vinegar/water solution, about half and half. Then I would set it up as if it were a new tank. Add filter, heater, gravel, decorations etc and fill the tank and add your water conditioner. Let everything run for a couple of days. The best rule for freshwater fish is when the air bubbles inside the tank disappear, the tank is ready for fish. Remember the tank will have to cycle again so you won't be able to add all of your new fish at once.

Another problem you might have is with the fish you selected. Guppies and Mollies together is a hit and miss, meaning sometimes it works, sometimes not. Both male Guppies and male Mollies can be very aggressive. I do know some people who have had success with it, so you just have to try it and see. The best ratio is 1 male to 3 females for both Guppies and Mollies.

Hope this helps, good luck!

Richard