[Drsites]

The thought occurred to me, and I'm not sure if I've positively identified a reason this couldn't work, so please, someone give me a good reason! My thought is why couldn't I run a stocked freshwater tank with good filtration as my ATO, then just refill the freshwater tank with RODI water as a partial water change? Are there bacteria that occur in a freshwater tank that would/could hurt the saltwater tank? Or would the bacteria just die, causing continuos ammonia problems? I feel like this is one of those things where if it worked, someone would have already done it. I can imagine some pretty cool ideas for set ups, like a species specific tank hosting macro as a 'fuge on one side of the DT, and a freshwater top off tank on the other.

 

[GOSKN5]

I think phosphates, nitrates etc would be the issue... its near impossible to have zero in a freshwater tank... bacteria etc probably wouldn't cross from fresh to salt...

I'm guessing here but that would be my thoughts

 

[Drsites]

I wouldn't think the levels of phosphates would be an issue so long as the main tank had the capability of using it, but I don't know what sort of levels a freshwater tank carries. Obviously a little research will answer my questions, but I figure there is a remote chance that things would balance, and the freshwater tank would just serve as a nutrient importer to the DT.