Stage 3 - Plant food

I'm guessing the plants/veges will get their nutrients from...

1. good soil
   our garden soil is both good and bad. The bad is that you just have to dig less than 6 inches and you will hit clay and rocks. The good is that the top 4 inches or so is really healthy looking. Grass and whatever existing plants grow well. It is full of earthworms and other little creatures.
2. compost
   we will try to start compost bins to add to the soil health.
3. fish waste water
   I have 2 aquariums inside the house. Ever since we started using the waste water to water the garden, we noticed that many plants responded well. Hope it will help with the veges to come.
4. Epsom salts
   I just found out about this. It is not like the salt we use for food. It's magnesium sulphate which plants need for healthy growth.