Here is the full list of all 30 Aquarium Designer achievements.
Keep at least 3 different fish or plant species alive for a week in the Realistic Mode aquarium
Get all the achievements
Feed fish 300 times
Make the fish tank dirty
Allow 300 fish to die
Allow 300 plants to die
Change the filter for the first time
Get 100% of points for 20 contracts
Complete 100% of contracts
Create 9 fish tanks in Casual or Realistic Mode
Spend 10000$ money
Unlock 100% of store items
Get 100% of points for 15 contracts
Complete 60% of contracts
Get 100% of points for 10 contracts
Unlock 80% of store items
Remove 300 things from the aquariums
Place 300 rocks in the aquariums
Complete 30% of contracts
Get 100% of points for 5 contracts
Unlock 60% of store items
Place 100 fish in a single fish tank
Create your first fish tank in Realistic Mode
Create your first fish tank in Casual Mode
Clean the fish tank
Unlock 40% of store items
Unlock 20% of store items
Complete the second contract
Complete the first contract
Start your first contract