As I wrote a few months ago, towards the end of last summer we got tired of having no successful tomato plants in our vege garden and set up a hydroponics system. We've been running it nearly continuously ever since. The tomatoes did die off in August when we had a heavy frost, but we replanted as soon as it warmed up enough in September. The joys of a sub-tropical climate ! I am so happy we set up the hydroponics, we have had nearly a continuous supply of tomatoes, and once its set up its very easy and cheap to run. I wrote all about the system we use in my last post. This time I just want to share a few extra tips that I've learnt since we've been running the system again. Monitoring nutrient levels While you can set up the hydroponics system quite cheaply (any large reservoir, a pond pump, some old pots and gravel, and you're away), you do need to spend a bit of money on a conductivity meter to monitor the nutrient levels. You can just chang...