hi i have a 6 month old gsd when is the best age to get another puppy

It would be best IMO to wait until your first dog is at least 18 months old...2 years would be even better
Archer

I would say 2 as well

Agree with Moonmaiden and archer. don't even think about it until your current dog is 2/3 yrs of age. :)

If you wait until your present dog is five or six years old the new pup will give your older dog a boost, the well-trained older dog will be a moderating influence on the young pup and accidents aside you will never be without a dog if you look for an eventual replacement for that young pup fives years on from then.

If you wait until your present dog is five or six years old the new pup will give your older dog a boost, the well-trained older dog will be a moderating influence on the young pup and accidents aside you will never be without a dog if you look for an eventual replacement for that young pup fives years on from then.

That's an assumption about an older dog needing a boost at 5/6 years of age, if a dog hasn't had experience of puppies/other dogs in the household  might not accept a puppy or another dog at all(I had to collect a puppy from just such a situation even though the older dog was fine outside the home with other dogs it would not accept the puppy & was aggressive towards it & I do mean aggressive, I have never seen such aggression towards a puppy by a bitch before & the puppy was a male)

Not eveyone wants to have such a big gap between their dogs as 5/6 years & the earliest I would advise a pet owner to get an addition dog is  years of age, young enough to adapt to a puppy & old enough to teach the puppy it's social manners & behaviour