I have just acquired one of these. Mine is almost 6 inches, I'll post on here instead of my ID thread. It seems to poop like a terrestrial animal, lizard or something and not a fish. I know I keep posting this but it really amazes me for whatever reason, perhaps its the size my 6 inch fish drops 1" nuggets every day, don't know what to make of this besides the ammonia issues its creating in his 20 gallon QT tank. I expect from reading around these animals suffer the same fate as many brackish fish. Novice keepers get and kill them making them get the label... DIFFICULT TO KEEP. I have made an unnofficial carrer of keeping brackish fish in fresh water similar to fugupuff. I've found brackish fish seem to do very well in fresh, well as any of my fresh water fish if you do a few things.
1. pristine water, though the fish actually does well in poor water as they typically live in or near sounds where water quality and parameters vary drastically on a seasonal basis they don't have a strong immune system. It has been hypothesized that many brackish fish use the variable salinity levels to deal with parasites etc as such if you keep them in poor water conditions you crush what little immune system they have. Long term exposure in such a system will make them more vulnerable to fungus' etc. than other fish.
2. Hard water is preferred, again while they do well with swings from different ends of the spectrum their naturally base is hard water. Beware of overly high metal content in hard water if your tap is obscenely hard. many of these brackish beauties are scaleless and don't deal well with high levels of metals relative to other fish.
3. WARM WATER! Most of the brackish fish in question like monos, stone fish, freshwater morays, etc. come from extremely tropical waters and prefer a resting temp closer to 82 or so degrees and will stop eating and prolonged lower temps.
4. Varied diets, if you are feeding a G. tile or other live food heavy animal like a stone fish don't get stuck in the rut of feeding similar foods. They will get HITH or lateral line problems. I for a long time attributed this to fresh water but found that it was actually a dietary issue not a salinity one for my fish. Raising salinity didn't fix it but changing dietary things up regularly did immediately.
These are the tenants of my care that let me keep a G. tile for just over 3 years in fresh. Monos for a similar length of time and leaf fish etc. I hope to use them with this fish to good effect. I'm still learning because doing so is still not a well documented practice and is regularly frowned on. After conquering this fish i hope to do the same with orange chromides, a fish that always ends up in my possession at the worst of times in the past, as well as Colombian sharks.