What are the differences in maintaining a saltwater tank vs a brackish tank?

[homersimpsonlikesfish]

What are the differences in maintaining a saltwater tank vs a brackish tank? I'm tempted to also keep a brackish tank, but do I have to be super accurate with maintaining a salinity of 1.015, or 1/4 cup marine salt per gallon, or can it be flexible because brackish fish can tolerate a range of salinities?

And also, do I have to use distilled/RODI water for a brackish tank? Or can I use tap water?

 

[KrisReef]

The best answer (imo) is that for fish health using RODI for marine or brackish tanks is going to provide the best water possible for your aquarium fishes. Marine tanks need more salt, otherwise you just need a good salinometer to make certain that the levels are stable.

While brackish water are perhaps more able to tolerate salinity fluxuations most fishes will do better without changes in salinity in an aquarium,

The routine maintenance (wiping glass, water changes) are going to be similar in salt to brackish, but I am not certain if brackish might be somewhat easier with lower calcium depositing critters to obstruct the glass? I'm guessing that this might be the case?

The other issue of tap water and brackish is that some of these fishes may be able to handle tap water impurities better than common marine aquarium fishes, so tap water may be a more viable option for brackish fishes? Before I kept reefs I used tap for mixing up fish tank water and had moderate success, but that was a long time ago and I wouldn't use tap now just to save a buck (given that my current tap water is pretty rank.) A clean well or rural water supply may be excellent for mixing Saltwater, can't guess without testing it.

 

[ISpeakForTheSeas]

Yeah, too much fluctuation in the salinity would still be bad for the fish (their bodies take time to adjust to different salinities), and RODI is ideal because it gives you a clean base to build from - you don't need to worry about potential toxins or other issues with it, whereas tap water might be fine or problematic depending on your home's source water quality.

 

[dennis romano]

A long time ago, as an undergrad, I spent two weeks in the Everglades studying the ecosystem. As the tide went out, it pulled fresh water from the north, lowering the salinity. As the tide came in, it brought ocean water. I ran a brackish tank with a scat, monos and mollies and it was really cool. The only decorations were driftwood branches that the fish swam through.