Monday, May 26, 2008

Changing the pH of my water

I'm told that the pH level of my water for the plants should be between 5.5 and 6.5. Mine is around 8.0 right out of the tap. If I let it sit for about 3 days, it does drop to 6.5 to 7.0.

I need to replace the water in my reservoir because I want to change the nutrients I'm using. I decided to use some pH down acid to lower my pH before I added the nutrients.

The directions on the pH Down were not very helpful. It simply said to use it "sparingly" and "a little at a time." What does that mean? I'm mixing with more than 10 gallons of water.

I decided that "a little at a time" was about 1/4 of a cup for 10 gallons of water. If you've used this before, you're probably laughing at me right now. It dropped my pH level off the chart. The test was bright red.

I dumped out the water and started again. I decided to start with one teaspoon in 10 gallons of water. It was still too much. My color was still orangish red.

I dumped out half of the water and filled it up again. This time, adding no further pH down, the level was right on. So, it seems that 1/2 teaspoon is the right amount for 10 gallons of water when your pH level is 8.0 to start.

Expanding the AutoPot system

I've added four additional pots (two pairs of pots) to the original AutoPot system (see the previous post). I've learned a lot, and I think I have some interesting things to report for anyone else thinking of expanding the system. One thing you should know right away is that it may require more water pressure than you expect to reach the third pair of AutoPots.

Previously, I filled the main reservoir with 5 gallons of water (a little less than half full). This did not provide enough water pressure to reach the third AutoPot- at least not enough to achieve the water level needed to water the plants. I had to fill the main reservoir with 10 gallons of water before enough pressure was achieved. This means that I will need to use more nutrient in the main reservoir than I wanted (in case I need to change the water). It also means that I need to pay attention to the amount of water that is in the main reservoir more frequently. This defeats the advantage of the AutoPot watering itself. So, I'll probably get another reservoir eventually.

The other option would be to raise the main reservoir much higher than the AutoPots. However, I neither have an attractive enough base support for the main reservoir nor a sturdy enough support to do this.

Required tools:
  • Something with which to cut the tubing

  • A level

  • Shims

  • Tube clamps (see below)

To see how to assemble the AQUAvalve into the AutoPot assembly, review the previous post. One change in the expansion kit (from the previous kit) is that the tubing comes packaged with both ends of the tube pre-attached to the 6mm T-fitting. This creates a problem; because, you need to insert one end of the 6mm tube through the yellow screw-on collar. However, the end of the tube has been deformed due to shipping attached to the end of the T-fitting. Therefore, the first thing you have to due is cut off about 1/4-inch (about 0.6 cm) from the end of the 6mm tube. Otherwise, you cannot get the tube through the hole in the yellow collar.

In the photo below, you can see how the tubes arrive in the package. The manufacturer needs to change this packaging practice to keep the ends of the tubes from deforming.

In the photo below, you can see that the tube will not fit through the collar.

I used a pair of wire cutters to cut off the end tube. Make sure that you do not cut at an angle. If you do, cut again or use a knife to cut the tube.

Your next challenge is figure out how to connect all of the various systems together. The instructions show you how the system should be connected once you're finished, but it doesn't show you how to get there. It also doesn't tell you how to connect more than one expansion AutoPot to an original AutoPot system. This may be on purpose, as I discovered. It seems that two expansion kits added to a single reservoir is one more than ideal.

To connect even one expansion kit, you must cut the tube for AutoPot #1 and insert the T-fitting between the tubes as shown below (A). Next, connect the tube from AutoPot #2 to the remaining barb on the T-fitting (B).

In order to connect three AutoPot pairs to one reservoir, you must also cut the tube for for AutoPot kit #2 (B). Cut off a short amount of tubing from tube #2 and use it to connect both T-fittings together as shown below. I chose to cut tube #2 fairly close to AutoPot #2. The figure below does not show this well. The next image shows this better.

Unless you empty all of the water from your main reservoir, you will need to clamp closed the tube from the main reservoir. I used some office-supply paper clamps that are commonly available.

As previously mentioned, I needed to fill the main reservoir with about 10 gallons of water (nearly to the top) to achieve enough water pressure to reach AutoPot #3 with sufficient water.

Using a permanent marker, I marked the inside of the reservoir at the 5 gallon and 10 gallon mark.

After you've got water flowing to the system, I recommend making sure all of the AutoPots are level. If your pots are leaning one direction, one pot could be getting more water than the other. If the AutoPot is tilted front to back, the float may not activate correctly.

Use some common shims from the hardware store to shim up the AutoPots until they are level.

Sunday, May 25, 2008

Organic Weed Killer

Here's a highly-rated organic weed killer I found at the following link:


* 4 cups white vinegar
* 1/4 cup salt
* 2 teaspoons dish detergent

Use it in the cracks of your sidewalk.

Wednesday, May 21, 2008

My hydroponic tomatoes - using Autopot system

As part of my quest for optimal health, I've decided to grow my own vegetables. However, in mapping out my plan, I encountered a few challenges. First, I've never grown my own food, so I have a learning curve. Second, I live in Minnesota, where the growing season is fairly short. My goal is to grow food year round. To do that, I need to learn hydroponics.

The above photo is my first attempt at hydroponic tomatoes. The plant on the left is a Burbee Big Boy and the other is a Heartland. It's day three, and they're still alive. Today is May 20, and when I walked out onto the deck this morning, it was only 42F outside.

"How are you guys doing this morning?" I said to my plants, which also include a few stalks of asparagus (not shown). I interpreted their stoic silence as a sign that I've not lost my sanity or my plants.

The AutoPot system is a no-brainer way to get into hydroponics. Well, there are a few things to learn, but much of the complexity is cut out. The kit includes the trashcan-looking container on the left (it holds the water), the reservoir that holds its two pots and a magic float valve. The valve lets in more water from the tank once the plants drain the water to a specified level that triggers the float mechanism to drop. A bottle of plant food is also included.

I've used clay pebbles instead of soil as a medium to support the plants. These are basically rolled up balls of clay that have been fired. Apparently, they pop like popcorn in the kiln, making them light but strong enough for support and drainage.

To assembly the AutoPot system, you first attach the tube to the float. The tube connects between the water reservoir and the AutoPot float valve (the blue item in the photo below).

Next, you remove the shipping restraint from between the float valve compartments (shown below).

Next, you press the float valve down onto the T-bracket in the center of the AutoPot reservoir. This is inserted into the half-moon-shaped portion of the valve (below).

Next, snap the cover over the float valve. You can pop this loose to look into the AutoPot reservoir if you ever wonder whether or not water is flowing to your pots.

Next, place the included black filters into the pots (see below) and the included gold and black filters (gold side up) into the AutoPot reservoir trays (see below). The filters keep debris from the plant side from contaminating your water. The gold filters keep plant roots from entering the reservoir, becoming entwined with the holes that allow water into the pots.

Next, I added about an inch of the clay pebbles to the bottom of each pot to keep the roots from resting on the bottom (see below). I felt this would provide better drainage under the roots.

Next, insert the tube and rubber plug into the hole in the bottom of the main water reservoir. Insert the plug until the oval disk is flush with the side of the tank. This will be the most difficult part. One tip is to moisten the rubber plug before insert it into the hole. Another tip is to reach into the reservoir and pull the plug through as you twist it in on the other side.

Next, connect the water filter to the end of the tube inside the water reservoir.

Next, put water in your main reservoir. I put 5 gallons. I plan on emptying any remaining water in two weeks and adding fresh, so 5 gallons may be too much. We'll see.

I'm told that I should test the water and make sure it is around 6 to 6.5 pH level. I purchased a kit from Bachmann's. My tap water seems to be around 7. A guy at the hydroponics store told me that if I let the water set for 24 hours, chemicals that are causing higher pH would evaporate. So far, I haven't seen much change. I think I'll buy a higher-resolution test and test again. If it's still high, I'll buy some pH down liquid at the organic store. Of course, my neighbor has been growing garden tomatoes for years with this tap water, and they seem to like the water just fine.

Below is what the pots will look like if the floats are working properly. The water comes up just high enough to reach the roots of the plants.

I added plant food to the water in the main reservoir according to the directions on the bottle.

Next, I gently shook the dirt off of the roots of plants and put them in the pots. I filled the pots around the plants with the clay pebbles. I may have used more pebbles than necessary.

The AutoPot system is expandable. I plan on adding several more pairs of pots to the same main water reservoir. I purchased the initial system locally at Interior Gardens:
1620 Central Avenue NE
Suite #115
Minneapolis, MN 55413

It's a really fun store to visit. They specialize in hydroponics, but any gardener would love the store.

The system can be expanded by adding more pots. The water line uses a T-connector to split the line between the pots. There is a point at which you need to add a larger water reservoir to feed the pots- if you really go crazy adding systems. Below is a photo from, the manufacturer's web site. The photo shows two additional pots, but you can add many more.

Saturday, May 17, 2008

Autopot system for tomatoes

Today, I'm setting up my Autopot system for a couple of tomato plants. My plan is to learn how to use these during the summer, and when winter comes, I'll move the system indoors to have tomatoes year round.