Zest the lemons into a saucepan and then cut the zested lemons in half. Now juice them for 150 grams of lemon juice. Also add the water, the ginger syrup, the sugar, the agar powder and the gellan powder. Then mix this while and bring it to a boil for 1 minute. Once it has boiled pour it into a bowl and let it cool down in your fridge. Then transfer it into a blender and blend it into a smooth gel. Transfer half of the gel into a piping bottle and keep the rest for later.