Month: April 2012

Today is they day we were supposed to harvest our crop from the hydroponic lab. We did not have anything to harvest because of all the problems we have been having. Overall the system worked like we planned but there are a few changes we would like to change if we were to try again. They are:

• Add more fish so there is more waste
• Have the pump run on a timer so the system is not constantly running
• Make the fish tank bigger so we can support more fish and more plants

The next time we tried to do this system we would try these changes to see if we can improve on the results we got this time.

When we came in today we noticed that our plants have begun to turn brown on some leaves. There is also more of the brown substance on the plant bed and rock wool. We believe this is a build up of waste and/or mold which could be harmful to our system. We will need to do more research on this to determine the best way to solve this. We decided to move one of the rock wool outside of the cup to see if it made a difference in growth. We believe that the plants may not be getting enough nutrients so putting them directly in the water may increase the amount of nutrients they receive or it may drown the plants. The decision to make the change even though there are some risks was made because harvest day is on Wednesday and we wanted to see if we could get an growth by then.

We tested the water again today for pH, nitrates, nitrites, and ammonia. The levels were:

pH: 8.8

Nitrates: 10 ppm

Nitrites: 0 ppm

Ammonia: .25 ppm

The nitrate and nitrite levels are in the correct range because nitrates should be below 40 ppm and nitrites should be around 0 ppm. The problem we are still having even after adding chemicals that are suppose to work is that the pH and ammonia levels are too high. The pH should be around 6-7 and it at 8.8 and the ammonia level is at .25 ppm and it should be at 0 ppm. I added some pH down to try and lower the amount of pH in the water. I would have added more ammonia neutralizer but it says to not add to much per week. We will continue to monitor these levels in hopes that the will balance out and our plants will grow more.

Here are some pictures of our aquaponics system today. The plants are still not growing even though we’ve added different chemicals to try to neutralize the water and promote plant growth. We tested the pH and ammonia again and they were both higher than we want for our system despite attempts to lower both of these. The pH was over 8 and the ammonia was .25. The pH should be lower than 7 and the ammonia should be 0 so we still need to lower those numbers for our plants to grow. I added some more neutralizer to try to lower the ammonia level. Before I did that we added water to the system because we are still losing a significant amount due to evaporation. We will continue to monitor our levels and add the neutralizer to get the levels to where we want them.

We are having some problems with our plant growth. We decided to test the nitrate, nitrite, ammonia, and pH again today to try to solve the problem. The nitrate and nitrite levels were at 0 but the ammonia level was at .25 which is higher than the book suggests. We had already lost some water over the weekend and we took some more out and replaced it with distilled water to try to solve the problem. We also are going to feed the fish less because we noticed that there was some food settled at the bottom and over feeding can lead to high ammonia. We hope that these fixes will help solve our ammonia problem and even our pH problem which was over 7. If we can fix these problems the plants should start to grow again.

Another group gave us two of their fish today so we added them to our system in hopes that it will make our system better.

Today in class, George and I lost some water in our fish tank. We added more distilled water to keep pH levels down. We checked our pH levels again after adding water, but we were still high, close to 8.5.

Dr. Brusic brought in a new, more accurate type of pH, ammonia, and nitrate tester. We decided to test our pH and ammonia levels to make sure our system would work properly. When we checked the pH with the new tests, it was much lower than we expected at about 7.4. Our ammonia levels were at 1.0, which can harm the fish, so we added an ammonia neutralizer to deal with that. Maybe our plants will start to grow more easily now!

We noticed that the water was down a few inches again today so we decided to add distilled water because the pH of the tap water we have been adding is higher than the distilled. We hope that by adding distilled water and some new pH down on Wednesday we will be able to get back into the 6-7 pH range because we are still in the 8.5+ range. The plants do not look like they have been growing as much as they had been early on. We believe this is due to the pH being so high therefore when we bring the pH down the plants should start to grow again. We will continue to monitor the pH and water levels so hopefully our plants will grow better than they currently are.