Sam and Rob's Radish Blog

Since today was the last day before our hydroponic system was due, there wasn’t much work we could do on the system itself. We filled the nutrient solution with a gallon and a half of water. Based on our research, we learned that as the water evaporates from the reservoir, it is necessary to fill it back up with water to dilute the nutrient level.

We also checked the pH level and temperature of the solution, which we’re pleased with.

7.0 pH

73.1 degree Fahrenheit

Lastly, we finished our documentations and technical drawing.

We have some good things to mentions as well as some not so good things.

I’ll start with the good. The four plants that are growing in the rockwool look pretty healthy, although some more than others. Three of the four have roots growing all the way through the rockwool and into the nutrient solution. The plant who’s roots have not grown down to the nutrient solution definitely looks less healthy than the others (its leaves are slightly wilted).

Now the not so good. As you can see, the plant in the upper left cup within the picture–the one growing in Perlite–has basically died. We now understand that the Perlite was not providing a moist enough environment for the plant, which didn’t even allow the roots start growing. Also, the three other cups full of rockwool have not produced any plant growth. As of now, it’s too late to replant anything, so we’ll leave the system as it is and continue showering our attention on the three healthiest plants.

Unfortunately, our first sprout seems to have taken a turn for the worst today. Droopy and still not making any progress of finding its way through the perlite into our tank full of the nutrient solution, it cannot feed. We’ve tried manually feeding it, but we cannot keep that up over the weekend. We are ready for the worst when we get back, it seems that anything we tried to grow in the perlite just wouldn’t work. We suspect it is because of the rather large size of the pellets, which leave little room for any potential roots to maneuver through.

We were absolutely thrilled today to find roots hanging down into the nutrient solution from two of the cups. The healthiest looking plant definitely has the longest roots, which extend a few inches out of the rockwool. We’ve been waiting for this to happen for quite some time because it usually means the plants are growing properly. We are hopeful that the other plants will eventually extend their roots into the nutrient solution as well.

The lone plant growing in Perlite does not look as healthy as the ones in rockwool, but it’s much to late in the semester to germinate and plant seeds for a third time, so all we can do now is wait and see if that one hangs on to survive.

pH: 7

Temp: 77.6 degrees Fahrenheit

After returning from the long weekend we were delighted to find our change had paid dividends. Four additional sprouts appeared, in each of the cups we planted a single seed. In the double seeded cups we observed only minor changes in the seeds, still seeming to be in a germinating state. Our pH has also receded to an acceptable level of 7.0.

Since we first planted our seeds, only one has sprouted. We decided today that something must change. After some further research, we decided to make a few minor changes to our system. We left the one sprouted plant in its cup full of perlite, but we cut a few more holes in the bottom to increase the oxygen that reaches the roots. For the seven other cups, however, we made more major revisions. Since we’re worried about the lack of moisture in the cups, we cut out the bottoms of the Dixie cups and replaced the perlite with rockwool. We’re hoping that the rockwool will absorb more of the nutrient solution and help the newly germinated seeds grow. We’re looking forward to seeing how the plants have progressed when we get back to class on Monday!

We noticed that a layer of calcium has built up on the sides and bottom of the aquarium. After stirring up the water, the calcium came off and made the water extremely murky. I did a little research, and many people recommend using vinegar to remove it. We’re planning on waiting until after the weekend to clean the tank. On Monday, we’ll empty the tank, scrub it down, and fill it with fresh nutrient solution.

Today marks the start of our second set of seeds’ germination. We’ve noticed one of our seeds has already began to germinate after sitting in a paper towel soaked in nutrient solution, similar to our first set of seeds. We are going to continue to let them germinate for an additional day, then will begin to plant them tomorrow.

We’re pleased with the water temperature, which is at 75.4 degrees Fahrenheit.

We decided to add a second air stone in the solution reservoir. Using only one rock stone in our five gallon aquarium wasn’t cutting it, so we added anther one for increased oxygenation in the water.

Since only one of our seeds has sprouted, we’re concerned that the other seeds will never start growing. Therefore, we placed seven seeds in a wet paper towel moistened in nutrient solution to germinate over night. If we find that any of the seeds have started germinate tomorrow morning, we will plant them in the perlite and replace them with the dead seeds.

We’ll be keeping a close eye on our only plant and keep you all updated on its development.

We tested the pH level of the nutrient solution in the reservoir, and we found that it’s at 7.5, which is slightly too basic for the optimal radish growing environment. We want the pH level to be between 6.5 and 7.0, so we added a pH Down solution. This should do the trick, but we’ll be wary of this in the future.