HI :)
It's been said already, but there is no set amount. Generally one waters slowly until a little runoff appears, making sure the entire soil is moist.
With AllMix, including organic fertiliser, watering can be a little trickier. AllMix comes with microorganisms in it and your organic fertiliser may be adding more. These organisms cannot live in dry soil and are very helpful for your plant. Hence, you want to keep AllMix moist at all times.
At least, the soil your roots are directly growing through should always be moist. Not wet. Moist.
Also, keep an eye on the ph levels ;)