Hydroponics In Space

SEE HERE For long term habitation in space it will be essential to grow your own food and recycle just about everything, especially water. The sheer difficulty of creating a closed cycle system will I think deter long term habitats in space until the technology can be perfected. Hydroponics is likely to be an important part of the ecology of a long term space colony. One would expect that such a colony's eco-system would be quite fragile. A significant blight would destroy the harvest and likely disrupt the ability of the habitat to exist. Don't expect to see long duration space travel until these kinds of problems are solved.

Need a Scale

I like to keep track of my tomatoes and my diet, so I use one of these attractive and relatively inexpensive kitchen scales which use piezo-electric crystal stress sensors to make their determination of weight. I'm really impressed with them since the two I have are so reliable and consistent. You can take the thing you are weighing off and on and it always reads the same which is one of the marks of a good measurement system.

I use the scales to weigh both tomatoes and food. I'm on a diet that is really fairly simple — shift food intake from 100 calorie per ounce food to 5 calorie per ounce food and eat all you want. I've dropped 45 pounds since May which isn't too bad. I started at 272 and I was 227 this morning. My long term goal is 170 so I still have a long way to go. If anyone is interested I'll say more.

The tomato is a perfect fit into this diet since tomatoes are nominally five calories per ounce. I let the food consumption range up to about 20 calories per ounce (grapes) before I get a little stingy with myself. You need a handy little digital scale if you're going to do this kind of diet since you have to measure how much things weigh or guess, but measuring is better.

I exchanged links with Joseph Wright at www.digitalkitchenscale.org so you'd have an easy link to go look at these interesting little scales. The growing season is about done and now it's into the eating of the last red ones and the waiting for the green ones to turn read or enter the fried green tomatoes experiment.

The Last Hurrah ...

This is what the tomatoes on the deck looked like a couple of days ago as October weather slowly turned from mild to colder. We have not had the frost yet that will terminate the growing season but the tomato plants are all but dormant in the cool days and colder nights.

It seems time for a recap. Summer 2009 was not a good experience. The total yield was a meager 189 tomatoes (sounds like a lot but most were cherries or small varieties. The total weight from the plants was only 518.75 ounces. That doesn't count the many green tomatoes which are still on the vines, but it is the ones that ripened and are being consumed by the Lord and Lady of the manor.

The summary is: 1) the wick systems started off well but hit a brick wall composed of disease and sudden failure to draw nutrient. A variety of factors may be implicated and I'm not sure of the relative likelihood of any of them. 1.1) system may have become so nutrient imbalanced that it the plants could not continue to proper. I don't have any way to determine that. The total nutrient conductivity was in the 20-24 cf range which is fine. 1.2) lack of oxygenation ... I didn't oxygenate the wick systems. The early prospering however makes me think that may not be the reason. 1.3) a good fraction of the plants expressed relatively severe plant diseases, but some seemed rather resistant, so that is also a factor.

My rule of thumb for plants is about 10 pounds of tomatoes per plant and with only 32 pounds of tomatoes from quite a large number of plants this season was a disaster. The system that did best was the deck system which was just potting soil planters which were watered and occasionally fertilized with mostly Miracle Grow which one of my correspondents pointed out is not a hydroponic nutrient, but then these pot systems were not hydroponic. The second set of plants were just set into Virginia clay otherwise they did fairly well, but also had disease problems. The deck system has some disease problems as well.

On the whole this was a season that was severely limited by plant disease. In fact I've never seen some of the problems with tomato plants that I saw this year. I'm going to look through some of the sites which have pictures of various tomatoe blights and diseases and see if I can classify some of the problems I had.

I enjoy even the bad years because I learn a lot. What I mostly learned this year is to go back to NFT next year, even if the system is only a small one. These systems were low yielding and just as much trouble as the NFT systems have ever been.