Where to buy dry ferts?

[gy960]

Hey guys,

Where do most of u get dry fertilisers from (not online)?
Ferts: Potassium nitrate
Monopotassium phospate
Potassium sulfate
Csm+ B
I only know ecocityhydroponics but i could only find potassium sulfate on their online catalogue.

Thanks.

[Shadow]

Potassium nitrate is control items in Singapore, you need license to buy it. The rest you can buy from hydroponic shop