@ombomb
Fish Gatherer
As a basic rule of thumb, you should be aiming for 20x water turn over if you plan to keep soft coral in there, so ideally you should look for 500GPH+ although personally I think this works best from a combination of powerheads which will move the water around more of the tank than a single one.
I wouldn't recommend anyone started a tank without a reliable source of RO / DI water, which means either buying it locally, or more convenient and probably less expensive in the long run, buying a filter and making your own.
Don't worry about finding water from a mature tank, it's the rock and the bacteria it houses which makes the difference, not the water itself.
I wouldn't recommend anyone started a tank without a reliable source of RO / DI water, which means either buying it locally, or more convenient and probably less expensive in the long run, buying a filter and making your own.
Don't worry about finding water from a mature tank, it's the rock and the bacteria it houses which makes the difference, not the water itself.