Maintenance

Checked the nutrient level this morning and it was at CF=20 and everything was chirping along very nicely. I didn't add any water, but I did add a half-cup of concentrate with the goal of bringing the level up to CF=24. I checked immediately after adding the nutrient and got CF=26 on the concentrate entry side, and CF=22 on the diametrically opposed side, so I am imagining that it will come to equilibrium at about CF=24. Mission accomplished! Check it later.

A few hours later it looks like the system has stabilized at CF=23 ... so maybe I'll add a little more nutrient, but Jessica is painting the back door and bothering her at this point may get me painted.

Added a quarter cup of nutrient and waited a while to measure it: Currently the CF =26 so I'll just leave it there for a day or so. Seems like the water level is down more than I would expect. I'll let it go through tomorrow and look at it again on Friday morning.

HARVEST 2010
6-30 SQUASH took two out of the garden today (1st Fruit) 5 7/8, 7 3/4 ounces. Great start! Film later ...

Topping Off and thinking ...

Well on the morning check I found the CF=28 which is a clear indication of a lot of transpiration without uptake of nutrient and the level was down. We've had a hot couple of days and the plants are getting quite large. I topped off the system and checked the nutrient level. It had dropped to 19, so based on the observation that a quarter cup of concentrate elevates the nutrient level about 2 points I added a half cup. I'll check a little later to see if that took it to 23 which is what I expect.

A little later has come and gone and the equilibrium seems to be about CF=22 so I'll add another quarter cup of concentrate later. So in summary I topped the system off on the 25th and now on the 29th I topped it off again so it's running down in something like four days in the current weather. Still from the standpoint of maintenance this has been the least work of any system so far. It's also pretty safe since you don't have to worry about power failures since all that does is turn off the oxygenation and circulation pumps or a while but it doesn't keep the plants from getting nutrient which happens in my NFT systems.

This has me thinking about how float systems could be enlarged and improved. I've done tubs in the past and they worked especially well for things like lettuce and basil. So far this float system is working well for tomatoes, although I'm still concerned that as the fruit set and the plants get heavier that the weight will sink the floats and the support system, which was improvised from tomato cages, will prove inadequate for its use. We'll see. That's one of the fun things about being a hydroponics hobbyist.

The Garden In Perspective

The garden is a patch in the backyard that is something like 12 to 15 feet approximately on a side and it has 8 corn plants, 12-15 tomato plants and a slug of yellow squash so I thought I'd give a little picture and a little perspective.

As you can see from the shot at the right the float system is nearer the house and it's around 3 and a half feet in diameter or there abouts. The garden plot can be seen in the background. Mostly I've just been watering the garden and as you can see the weeds are loving it, but so are the plants and they have a head start.

Status ...

Well after equilibrium the float system settled to CF=23 and I've not bothered to increase it. The garden tomato plants are doing well and I'll put some pictures of those up in a couple of days. I've got 8 corn stalks, a whole slug of yellow squash, and about ten or twelve tomato plants in the garden. They are not as lush or advanced as the tomatoes in the float system, but they are coming along too. There are lots of bloom on the squash and so far two little yellow squash are out there lying on the ground. The weeds are doing well too, but since the plants had a head start most of the weeds are pretty far behind.

Refreshing the Nutrient: Easy Since There Is Already A Pump In The System

Well it seemed like a good time to refresh the nutrient. If you leave nutrient in a system and just replace water and top off the nutrient if there is any imbalance it tends to increase and ultimately cause problems for the plants. So this morning I went out and swapped a lot of the nutrient by pumping it out of the pond and dumping it on the garden which has not been fertilized.

I pumped 3 and a half buckets out before replacing it with fresh water and topping the nutrient off with 2 and a half cups of concentrate. That brought the CF to 22 but it was not in equilibrium so I'll check it later. Mission accomplished. The frames are working fairly well to sequence the plants off the float so that the support is divided. I don't want the floats to submerge although so far they seem pretty good. These tomato plants are doing markedly better than those in the garden.

Quick Update

Topped off the float system today with water and added 3/4 cup of blue and white concentrate. CF=23 but was not necessarily at equilibrium. I'm going to be curious to see how fast the nutrient level goes down now that the plants are getting pretty big and setting blooms and what not.

A couple of add ons ...

I forgot to mention a couple of things earlier. Just came in from measuring the system and got a CF=23 so I guess I have to confess that the earlier estimate was a guess and it was a little off.

Yesterday I topped off the system with water and mixed up a gallon of nutrient concentrate. You do that rather easily by mixing 17 ounces of white mixture into a gallon of water, and then 17 ounces of the blue mixture into a gallon of water. That makes two gallons, one of white and one of blue, concentrate. The general rule is one ounce of concentrate makes one gallon of nutrient (that's one ounce of each mixed into the gallon of water ... you can't mix the concentrates at full strength because then chemical reactions take place that precipitate out some of the nutrients, but when they are mixed at the delivery strength they don't react. Don't ask me, I'm a physicist not a chemist, apparently there is a concentration requirement.). Anyway I'm not sure how much water is in the pond because I didn't measure it, just added nutrient until I got the readings I was looking for. A quarter cup of concentrate moves the CF in the pond about 2 points.

At some point it will be a good idea to pump the nutrient over the side and maybe use the old nutrient to fertilize the garden and refresh the nutrient in the pond. The reason for that is that the nutrient is balanced for tomato plants but there is no guarantee that it will stay in balance and our instruments are too crude to tell since we only look at overall ion concentration. So every month or so it is a good idea to empty the pond and replace it with fresh nutrient.

There is some build up of algae in the pond, but not very much since most of it is not directly exposed to sunlight. All in all it's going well. The CF (Conductivity Factor) instrument I'm using is the truncheon which was developed in New Zealand. It works very well and I think they have skyrocketed in price to about $130.00. When I bought mine it was less than $100. I have two because I couldn't resist seeing what the new one was like. Turned out to be not too much different from the old one, just a little prettier. They are both working just fine.

Rats Nests and Jungles

Well there are ten tomato plants in this float system and they are getting pretty crowded about now so they need some sort of support and expansion system. So today I bought some of those wire supports that can be used with tomatoes. Generally they are mounted as triangles, but I just stuck-em in the ground and tried to surround the pond but giving me access at the near side in this view. You can also see the electrical hook up to the two pumps. One pump is the fountain which is hopefully supplying the oxygenation of the water, and the other pump is just in there providing circulation in the hope that they will deter any mosquitoes that come by.

Here's the garden, well a portion of it anyway. These tomatoes were planted in rockwool at the same time. They are flourishing well enough, although it is hard to see them clearly with all the weeds that are starting to flourish too. This is why I call it "The Weedless Garden" when I use hydroponics. I am not, repeat not, going to go crawling around in there digging up the weeds. The tomatoes were all planted in a cup with the bottom cut out to head off any cutworms and also gives you a target if you want to fertilize which I have to confess I have not done so Jessica was on my case today because she doesn't think it is fair to the plants in dirt not to fertilize them when the plants in the float system have total access to nutrients. So I'll probably do that.

It will be fun to compare the tomatoes when they come off the vines and see if there is any difference. Anyway I'm going to be trying to get the tomatoes in the float system to come out and so that they are not so crowded, get them to grow into the supports. We'll see how well that works. Overall I'm quite happy with the system. The plants are growing well despite being crowded. CF=22 right now. I've added water only once or twice since June 4th and maybe a total of a cup of nutrient (cup of both white and blue). I have not been logging it. I should but this system has been so easy I just haven't been.

What A Difference a Week Makes!

I was a little concerned about how taking a trip to Groton, CT for a week would work out. We went up there to see our youngest son graduate from Sub School. That was quite cool! We also visited the U.S.S. Nautilus and an active duty Los Angelos class attack boat, the U.S.S. Providence.

The whole while though I was a bit concerned about the float system. I had topped it off and left it completely full of water and with the nutrient running at CF=22. So when we got back late on Tuesday I ran back into the backyard with a flashlight (we got home after dark) and looked at the system. All seemed to be fine. It was about two inches down and the CF was 22. Today, the 10th, I took a picture to put up here. As you can see the plants have grown quite a lot. I still don't have a support system set up or even thoroughly worked out, but that is next on the agenda. The plants in the float system are more robust, larger and more vigorous than the plants that are in the tilled soil in the backyard. (See Below)

Morning Ministrations

Well this morning I went out and turned on the sprayer (a little fountain kind of thing) to water the small garden plot. While I was at it I went over and measured the conductivity factor of the float system and was quite surprised to find it at CF=18, down from the value of 20 which I was expecting it to be at. So I added another half cup of blue and white nutrient concentrate to bring it up to a robust CF=22.

Maintaining the System

First addition of water occurred today. I'm quite curious to see how well the system responds to neglect. So far, with the plants being quite small as yet, the system has required little attention. Today I topped off the liquid in the pond taking it up close to capacity adding something like 2 inches of water. Before the water was added the CF=21 and after the water was added it had fallen to about CF=17 although I didn't wait for it to gain full equilibrium. I added a half cup of blue and white Total Gro Steiner concentrate and that appeared to return the pond to nominally CF=21. I'll check tomorrow to see if that is what it is at when it reaches equilibrium.

I've not yet mixed up any new concentrate so I'm using up the last gallon of concentrate that I had from last year. I'll probably have to mix up more before long. To mix my concentrate I mix one pound of blue nutrient power into a gallon of water and then a pound of the white mix into a different gallon of water producing one gallon of blue and one gallon of white nutrient concentrate. One ounce of concentrate (both blue and white) added to a gallon of water produces a gallon of nutrient at CF=24 (roughly).

So far the plants look great and somewhat healthier than the similar plants planted in the rototilled patch (about 15'x15') in the back yard. I've added no fertilizer to the backyard patch which may contribute to the fact that they look a little more anemic and have some yellowing of the lower leaves. I'm thinking of that patch as something of a control against which to measure the progress of the little float/pond system.