Changing Fresh To Brackish

[redrochelle]

So I've had my tank set up for almost 4 years. A year ago I bought a dragon goby and his always been in fresh water so I want to make my tank brackish. the question that I have is do I have to take out the water that I have since it has fresh water salt in it? or can I just start adding my marine salt with everything the way it is? I'm taking out the fish that are fresh and putting them another tank and then turning my 40 gallon into the brackish. I need to also use sand or will gravel work? and will the light I have work as well or do I need different lights? Thanks

 

[nmonks]

Nope, you don't need to change anything. Each time you do a water change, replace the water you take out with brackish water. For Violet Gobies you should be okay with as little as SG 1.003 at 25 degrees C, which is 6 grammes of marine aquarium salt mix per litre of water (you can use my Brack Calc application if you want to use US units). Keep doing that, and after a few weeks your tank will be brackish. SG 1.003 at 25 C is low enough most hardy freshwater plants will do fine. Many "freshwater" fish will tolerate this fine too: guppies, horseface loaches, rainbowfish, etc.

Smooth silica sand (e.g., pool filter sand) is better for Violet Gobies, that's for sure. Gravel tends to scratch them when they burrow.

Cheers, Neale

So I've had my tank set up for almost 4 years. A year ago I bought a dragon goby and his always been in fresh water so I want to make my tank brackish. the question that I have is do I have to take out the water that I have since it has fresh water salt in it? or can I just start adding my marine salt with everything the way it is? I'm taking out the fish that are fresh and putting them another tank and then turning my 40 gallon into the brackish. I need to also use sand or will gravel work? and will the light I have work as well or do I need different lights? Thanks