DWC babies have grown up!

It has been almost three weeks now since the last post. I have only let the system run in peace, two weeks ago I added another 25 ml each of Gold Label A and B. My beans are showing some spots on the leaves which I think is a sign of too little nutrients. I realized I will not be able to guesstimate the amount of nutrients needed all the time so I ordered myself an EC meter from eBay. The EC meter is called HM Digital COM-80 and I got it for $40 and another $12 for shipping.

HM Digital COM-80 EC meter

This meter can measure the electrical conductivity (EC), total dissolved solids (TDS) and the water temperature. It can measure EC in µS and mS, TDS in ppm and ppt. Fancy. I hope I don't have to care about all of this. I found a chart of different desired ppm levels for different plants so this is the only measurement I care about at the moment.

Measuring the ppm of the nutrient water

I tested the ppm level and it was showing 120 ppm. Beans apparently need around 1400-2800 ppm. Maybe not when they are still fairly small. I was so smart when I decided which plants should go into the DWC system so I picked plants which likes the same amount of ppm in the nutrient water. No, I did not think of that at all. Anyway, I flushed the water and added a new batch of water and nutrients.

DWC system today

So this is how it looks right now. The beans are going crazy even though it had that little nutrients. Not sure if you can see the weird spots on the leaves. My Grand Rapids lettuce appears to dislike this environment. Maybe it's too hot. Also, lettuce needs about half or a quarter of the ppm that the beans need. Doh.

On the upside the Chinese Kale is doing great and the Holy Basil and the Chili have grown pretty good, almost as good as their brothers which was planted into soil. Can not tell anything from that since they have been placed on the other side of the apartment which has the most sun.