CO2 can stabilize using portions of anaerobic, aerobic and decomposition microbiology in an enclosed eco-sphere. Adding more plants and soil in the CELSS system, Part 1, click here
Below is a view from the top of the opened CELSS system. There are three plants. Two are growing in soil (back or top of the picture) and the third in water (lower part of the picture).
Another view looking over the water portion of the tank.
Below is a live picture of the CELSS system. Each picture is taken once an hour. Parts of the blurred picture are condensation on the glass. If there is no picture at the time, the system is being worked for updates. Please come back a bit later.
This system has been closed since Oct 14, 2012. It is opened today, Nov. 11, 2012, for updating Firmware and adding a few new sensors. When the system was closed up, CO2 levels were over 10,000 ppm. At that time, newly installed plants were introduced. Adding more plants and soil in the CELSS system, click here. It was planned that additional plants would stabilize the CO2 levels. LED lights are cycled on for 16 hour per 24 hours instead of 12 hours. It takes time for the gas cycle to stabilize. There are several balances being achieved. They are methane, nitrate, oxygen and carbon dioxide.
The carbon dioxide cycle starts with decomposition and plant metabolizing sugars to grow. In this case, the big contributor of CO2 is decomposition. In Part 1 the Ammonium and Nitrate cycles are balanced by allowing the bacteria to colonize on the tank walls and on objects in the water. In Part 2 CO2 and O2 need to be balanced while continuing to monitor the Ammonium and Nitrate cycles.
The progression of balances are done one at a time. Each balance action needs time to grow into its container. It’s important make sure all of the biological elements are in place before going on to the next. The goals for the system are as follows:
Amonium-Nitirate Cycle (Ranges: almost 0 ppm when no obvious decay is occurring, grow a colony when a decaying operation occurs does not push the Nitrites over 5 ppm)
CO2 – O2 (Ranges: CO2: 200 to 1300 ppm cycled per day, O2: Air: between 10% to 22%: Water <10.0 mg/L)
Methane – Ozone (O3): (Ranges: TBD – I’m not there yet!!!)
Before closing up the tank for a month, the O2 in the water was around 10.5 mg/L. This is way too much dissolved O2. Four goldfish died and started to decompose. I don’t believe the fish died because of too much O2, but the temperature in the system went up to 26 to 28 C degrees. The temperature killed then; however, I have no proof of that. I will try fish again in a week. The Amonumum and Nitries in the water reached around 0.5 ppm. CO2 maintained around 10,000 ppm at night and during the day; the CO2 went down to 8900 ppm.
After 4 weeks, the CO2 level went down to 288 ppm to 2200 ppm for a day cycle and the water has around 9.5 mg/L O2. All Nitrites, Nitrates and Ammonium are 0 ppm. There is no active decaying. Below is a picture of O2 bubbling out of he algae growing in the water.
The water chemical levels at this time are all 0 ppm for Ammonium, Nitrite and Nitrate. The pH is 7.2. DO in water is 9.5 mg/L.
As time goes on, the limits and ranges for chemicals in the system will be determined; however, in the beginning a roadmap needs to be established to determine relationships between chemicals, animals and physical properties. This is generally done using intuition. Afterwards, quantitative assessments can break through and measure processes and functions of microbiology, chemistry and physical properties. At the present time, a process of taking the existing system, as such as it is, and allowing it to stabilize for a period of a week or so. Change only one thing in the system to see how it reacts. Allow it to re-stabilize and then change the next thing. This is not the Scientific Method . There is no guessing what the outcome will be. Just observations. No pre-assumptions. I have always thought of the Scientific Menthod as an educated guess causing often unintentional biases. Observations can be in quantitative measurements (i.e. removing water from the system changes the humidity in the air by 10 %), or in black and white instances (i.e. turn off the LEDs for 30 days and see what is left; and believe it or not, it will still grow for a while in the dark).
The process of documenting the current stabilized conditions and then changing a single factor is extremely repeatable. If you create the same stabilized system and make a single change, the result repeats. It’s like a mechanical machine made from sturdy metal. The trick is to have a stable system; not making a change while the whole system is changing from one place to another. The hard part is knowing what to measure and how to go about measuring it.
Below is an above picture shot of the water, graduated cylinder and liquid/gas data collector.
Another picture. The board measures, RH, Temperature, Water Temperature, CO2, O2, Methane, Ozone, Air pressure and Air Temperature. About 10 years ago, this single board would require a ton of equipment that would need to sit on a table the size of a conference room. It’s technology wonderful!!!
High RH is a pain the butt with closed systems. The RH in an enclosed system ranges from 22% to 91 %, depending on temperature. And if the temperature in the system decreases around 10 C degrees, the RH goes through the roof. If the temperature in the closed system goes up 10 C degrees, the amount of water in the air is doubles, but the RH remains almost the same.
Pictured below are dehumidifiers used for keeping the RH down. They are thermal electric devices used for chilling salt water fish tanks. They are used in air. Every 45 minutes, they need to be turned off for 15 minutes. A clump of ice forms on the cold part of the device. The fans above help cool off the heat sinks.
Close up of ice forming on the cold side of the theermoal electric device.