PETG - for what do you use it?

[PatPend]

I use it for parts that come in contact with Diesel fuel.

[wirlybird]

I am using it still as an alternative to ABS. Once you get it dialed in it is pretty easy to work with.

[chappy6107]

do you know if pet-g is safe for use in an aquarium?

[Alibert]

Should be. PET-G is a modified version of PET (the stuff water/lemonade bottles are made of).

As polymer it will be just as safe as a bottle for mineral water or soft drinks. The additives (colorants) are unknown and I can not vouch for, but i do not expect any problems there.