Seeds and Nutrient

What should appear in my mail box today but not one but two seed catalogs. Totally Tomatoes and the Vermont Bean Seed Company. Seeing seed catalogs is motivational. Both of these catalogs are great. Since I'm mostly a tomato guy with a nod in the direction of cucumbers and peppers, the Totally Tomatoes catalog is usually the one I turn to first. The Vermont Bean catalog has a lot of other fascinating stuff though, so you might want to check it out.

I ran out of nutrient the last time I fielded a full system which was the Summer of 2007, we went on vacation instead and I injured my shoulder. The injury and resulting surgery pretty much kept me out of commission in 2008 so I did some image processing research on the shroud of Turin instead and gave a couple of papers at the Columbus Shroud Conference.

Now I'm getting geared up for Summer 2009 the year of the passive systems. The contemplation of a new system reminded me that I needed to order nutrient so I called TotalGro (SDT Industries) in Winnsboro, LA (1-800-433-3055) and ordered a 50 pound sack of their 8-5-16 Hydroponics Special/Steiner Formula. I've grown just about everything with that stuff. It's a two part powdered nutrient. I mix it up as a two part concentrate and then add it to my nutrient tank as required to maintain whatever nutrient concentration I'm using for the plants in question. The 50 pound sack is the minimum order and that generally will hold me from five to 8 years depending on how large my systems are. But even with shipping and handling it is less expensive than many hydroponics nutrients sold in liquid form in relatively small quanities.

Winter time is Design Time

Well it's been cold enough the last few days to convince me that even if it isn't Winter yet, Winter is on the way. Thanksgiving is next week and my youngest son will be graduating from Navy Basic Training shortly. I've begun sketching ideas for the coming Summer. I want to be able to take a vacation and not worry about my electricity failing and losing all my plants, so this seems like a good year to explore the wonders of passive systems.

Have you seen those dumb watering globes that some folks are peddling on T.V. You fill them up and stick them in your plant container into the dirt and somehow they are supposed to meter the water into the soil. I did a little web research and "surprise, surprise" the vast majority of the comments were very negative. They clog, they don't work right apparently most of the time dumping almost all the water into the soil immediately and flooding the plants. Why am I not surprised? A lot of those $19.95 for the miracle product things on T.V. are just con-jobs. If your experience differs, please let me know.

I mentioned that I picked up a couple of smart valves for one of the passive systems. Then I'm thinking about variations on wick-system design. The other thing I thought I'd do is try to figure out how to use inexpensive float valves to control systems but first I have to find some inexpensive float values — they all seem a bit pricey.

So what elements will I need? It's always a good idea to think about what you're looking for. I think I need: 1) A nutrient tank, 2) Some sort of feeder to feed nutrient into the plant sites, 3) cheap and reliable float valves that work well at low pressure (might just use toilet float values but I want something that is easy to modify), 4) A set of plant containers of some sort, 5) Passive media for the containers.

The Growing Edge Arrived ...

I got my copy of The Growing Edge Vol. 20 No. 2 November/December 2008 just yesterday and it has a nice article by me in it about getting started in hydroponics. Simple systems allow a person to get started in hydroponics pretty easily. It doesn't get any easier than a wick system or a float system. Pick up an issue and take a look. There are even a couple of pages from my notebooks.

More on Passive Systems

This is the time of year (mid-October) when my mind tends to turn to system design. What should I do next year. I've had two pretty tame Summers since I've taken a vacation last Summer and this Summer I worked on a study of image-processing and the Shroud of Turin which I hope will be up on the Ohio Conference Shroud site by the end of December. That tends to mean that next Summer it's back in harness growing tomatoes. But I want to take some time and drive around and visit some folks and now that our youngest son has gone off to the Navy there's no-one to tend the hydroponics system when we're away.
"If anything can go wrong it will" is one formulation of Morphy's Law, so leaving a hydroponics system to its own devices when it depends on the electrical mains is a recipe for dead plants. So I've been thinking about passive systems. I've mentioned wick and float systems. One passive system I've mentioned only in passing is the Auto-Pot system which uses a clever little device known as a Smart-Valve. Jim Fah invented this gadget and you can read about it HERE.

Jim Fah's Smart Valve and the Auto-Pot System

The Smart-Valve is the "brains" of the Auto-Pot system. It consists of a couple of interconnected float valves that both limit the height of the nutrient fed to a plant and prevent new nutrient from being added until the level drops to a predetermined lower depth. This little trick nicely simulates the way plants experience nutrient in the real world of dirt growing. I used one of Jim's valves on the Deck System long ago in Summer One and it worked just fine. I chose to use NFT instead in the intervening years, but I've always had a soft spot in my heart for passive systems. So a week or so ago I bought two of Jim's latest valves and I'm going to test a mix of passive systems this coming year to see just how much difference it makes to the plant to simulate the real-world nutrient cycle.

Passive Systems

Passive hydroponics systems have a lot of advantages. You might ask: "What's a passive system?" The short answer is one that doesn't need electricity to operate. The two easiest passive systems are 1) wick systems, and 2) float systems. There is a third form of passive system which is a bit more technically sophisticated, but not much, called an Autopot system. Let me quickly summarize each.

Wick Systems

Wick system are two level systems. The nutrient is in a tank below a cover and the plant is mounted on the cover with wicks which go down into the nutrient tank. The nutrient feeds up to the plant by capillary action and the roots of the plant follow the nutrient moisture down into the tank. It is completely passive and very easy to construct. Plants don't typically grow as vigorously in a wick system as they do in an NFT system, but they do well.

Float Systems

Float systems are usually best suited for plants that are fairly light since heavy plants with substantial support requirements will tend to weigh down the floats and submerge the system or the floats will have to be large. I have used floats very successfully to grow basil and lettuce. You get Styrofoam sheets to make the floats and cut holes for little plant cups in the foam. Since the system actually floats on the nutrient the bottom of the cups are in the nutrient so while you could use wicks they are generally unnecessary. Rather quickly the roots grow down into the nutrient. You can oxygenate the solution using aquarium air pumps but then you need electricity. My experience suggests that if you design your plant cups so there is a relatively dry interval they can get oxygen via that route. There's a photo of a float system growing basil in the sidebar.
I'll leave the Autopot system for my next post, since it is more complicated and deserves its own discussion.

Flowing Nutrient to the Channels

When I first started doing NFT (Nutrient Film Technique) hydroponics I would flow a large amount of nutrient through the channels by connecting a flexible 1/2 plastic tube from the pump and running it all the way to the end of the channel. This made for a lot of flow. One thing I noticed is that the tomato plant roots grew at an incredible rate and wound end up coming out the ends of the tube at the tank end and grow into the tank. Really long roots. By the end of the Summer in some years the roots would be so thick that the nutrient would actually start over flowing out the sides of the holes in the channels for the plants. That was just too many roots. I tried cutting down on the flow and that actually seemed to reduce the root growth.
In the picture you can see the way I feed my channels now. I run a piece of 1" PVC parallel to the channel (a piece of 4" diameter PVC with 3" holes on 17 inch centers) and drill a 6mm hole and thread a 1/4" piece of plastic tubing to a hole at the end of the channel. This restricts the flow and delivers plenty of nutrient to the plants. The result is roots that still grow rich and healthy but don't totally fill up the channels. It works really well.

Friends

One of the delightful things about hydroponics is the friends you meet. I have a folder on my computer that I put pictures that people who have read my articles in The Growing Edge have sent me. Some of them are pictures of systems modeled after some of those that I've built and others are just folks wanting to share their own excitement about hydroponics.
Jim Duffy's peppers, pictured above are an instance of the latter. You can visit Jim at http://www.refiningfirechiles.com/Jim had been growing hot peppers, and Jim tells me that his peppers are the hottest you can imagine. He lives down San Diego way where they know about such things. Jim started growing his peppers using NFT (Nutrient Film Technique) and they took off. Here's an example. Jim has never seen peppers yield like this and he's excited about it and shared his excitement with me. I was very flattered.