Problems and Solutions

1. Aphids

Aphids were the scourge of the greenhouse. They killed a large percentage of our plants, and caused problems with all the rest. About the only crops in the greenhouse that were resistant were onions and parsley; everything else was attacked to varying degrees. Wheat, though attacked, was somewhat productive. Many potato plants were completely killed, and those that survived the onslaught remain unhealthy.

We attacked the aphids in several different ways, with varying degrees of success:

· Hand picking: proved to be very time consuming, and while it worked well on potatoes it proved impossible to do on the wheat.

· A soap solution was sprayed twice a week for about a month. Although this eliminated the flying aphids, it had little (if any) effect on the immature aphids.

· A solution with pyrethrins was tried, with the same effect.

· Malathion also failed to do much more than the pyrethrins. Malathion was only used in a very limited area, for malathion is a chemical that causes problems in chickens. Since our chickens are living within Mars Base Zero, it was not possible to spray areas without posing a hazard to them.

· Carbon dioxide enrichment appeared to cause problems with the aphids.

· After we turned off the heat (starting the last week of April) the cooler night temperatures (down in the 50°F range) appeared to really repress the aphids.

Suggested solutions for next fall:

· Initially sterilize the entire building to attempt to prevent any infestation

· If the are re-introduced

o Maintain a day/night temperature difference, with the night temperature low enough to depress the aphids.

o Destroy any plants at the very first sign of infestation

o Maintain higher CO₂ levels

2. Heating problems

Furnace problems

As of May 1, 2000, Mars Base Zero has been continuously occupied for 6 months, since October 1, 1999. (Note: Mars Base Zero will be shut down for the summer of 2000 because of a lack of method to keep it cool--and no time to install one!) During October and most of November, the heating system consisted of a space heater which pulled in outside air, burned heating oil and exhausted directly into Mars Base Zero (note: a carbon monoxide detector was installed to protect against this deadly gas). This system proved to be very shaky, primarily because of the number of times you had to fill the space heater, thermostat problems, and other problems like power failures (or the plug coming loose), water in the fuel, etc. It was also slightly undersized for the amount of heat we needed, especially before we got the roof partially insulated. Additionally it put out ethylene, which was not a problem at this early date, but later on when the space heater was used intermittently as backup heat, it proved a serious problem.

We had a distressing number of heating failures. Although there were fewer failures during the 4 month study period than in the preceding 3 months, we still lost the heat on 7 different occasions:

Date	Minimum temperature	Comments
1/2/00	25	Space heater was turned down too far
1/5/00	60	We were there
1/15/00	17	Space heater ran out of fuel
1/22/00	50	Space heater
1/22/00	50	Space heater
?*	55	Sensaphone to the rescue!
?*	50	Sensaphone to the rescue!

*Date not logged because minimum temperature was not very low. Sometime after 1/26/00 when the Sensaphone was installed.

Solutions to prevent further heating problems:

· Bury the fuel lines to protect them from the cold

· Bury the fuel tank to help keep it warmer

· Attach a return line to the oil tank to improve fuel flow

Insulation

Insulation was nearly non-existent when we moved in. The east and west walls were nearly all there was that was insulated. Fortunately the structure was quite air-tight, or we would not have been able to keep it warm at all.

As the temperature dropped off in October we barely managed to stay ahead of the temperature curve, keeping the inside temperature at around 40°F by insulating the north half of the structure.

Solutions to reduce heating costs next winter:

· The structure remains un-insulated in large areas. Finish the insulation.

· The air-tight (vapor) barrier is not yet complete. Seal the vapor barriers.

· The north half only has one foot of insulation in it; add the second (planned) foot of insulation

3. Cooling problems

In early March the warm outside temperatures combined with the bright (returning) sun to cause severe heating problems in Mars Base Zero. A partial solution to the problem was a 24 inch fan was installed with a vent. The fan was hooked to an air-conditioning thermostat, so that when it reached 80°F (at the level of the plants) the fan would come on. Additionally we could open the door to provide extra ventilation. These solutions work to about 50° outside air temperature; after that it tends to warm up in the greenhouse as it warms up outside.

Near the end of April the furnace was turned off completely, to help keep the peak daytime temperatures down. This cause diurnal temperature swings of around 50°F (from 50 to 100°F).

The overheating prevented us from supplementing the air with carbon dioxide. for two reasons; first we would have wasted the CO₂, for it would have been mostly vented to the outside with the hot air. Second our method of enrichment was by burning propane, which gave off a fair amount of heat. Until the temperatures got too warm, we did reduced supplemental CO₂ at night.

Solutions have not been properly investigated for recommendations, though some kind of evaporative cooler is the most likely solution (an air conditioner will probably prove too expensive).

4. Watering problems

Our water supply is not yet hooked up. This was not a serious problem, for our water use never exceeded the amount that could be stored in any given week (3-30 gallon containers and a 55 gallon container; total of 145 gallons). To obtain water for the plants we ran a 100 foot garden hose over to the neighbor's house (which has a well). This water is very high in calcium, but with our low soil pH this will not pose problems until it begins to build up in the soil.

Solution: hook up the permanent water supply (a buried, 1" pipe between the Smyth's house and the greenhouse).

5. Gone/inadequate care problems

Due to problems with instructions to the person caring for the greenhouse during the 9 days in March we were gone, we lost an entire bank of wheat to a lack of watering.

Some of the preplants were over-watered during the same period, causing weaker plants which then succumbed to aphids.

Solution: better training, or hire a professional.

6. CO2 problems

Only at night after cools off, and not at all after it warmed up outside.

Solution: more artificial lights, block sun. (This is probably too expensive.)

7. Electrical problems

During the winter of 1999/2000 we wired Mars Base Zero in temporarily to the neighbor's power supply. We had hoped to be able to plug in 18 of the 1,000 watt grow lights (75 amps of the 100 amp service). Unfortunately when we plugged in the 9th light the circuit breaker blew. So 8 lights was all we could plug in; less than 1/2 of the number we were hoping for. (This may have contributed to some of the problems with aphids).

We currently have a total of 43 lights to plug in. This is 43,000 watts, or 179 amps at 240 volts. So, at first glance a 200 amp service would be sufficient. However we may want to add as many as 40 more lights (though this many lights may prove to put out too much heat), which would considerably exceed 200 amps. Also we have a number of things to run besides lights (furnace, water pumps, air conditioner, fans, etc). A supply of 300 amps would be nice, with 400-500 ideal.

8. Chicken problems

Too many roosters, not enough hens resulted in the hens being torn up.

· solution: segregate roosters, eat them

9. Strawberries

Irregular watering caused growth retardation

· Set up a watering schedule and follow it.

Inadequate lighting

· Install more lights

10. Soil nutrition

· low = needed 2 fertilize every 2 wks

· impression: need every 10 days

· only fertilized plants tt were up

Final solution

1. Obtain the desired soil fertility

2. Maintain it with compost.

11. Air flow too great

· Problem: heat loss and enriched CO2 loss

· Solution identification:

o although Mars Base Zero has a lower air loss than many greenhouses (estimated from CO2 loss to be about 1 air change every 4 hour) this is still way too high for doing closed system testing. Fortunately the highest loss areas are unfinished. The juncture between the greenhouse and the apartment is not yet sealed, especially along the roof line. The frost that formed on the outside of the building when it was cold out is an indication of the amount of air loss we had out this area. The arctic entry is designed to be pretty open to outside air to provide air for the furnace (a 4 inch hole is recommended!) Since the door between the kitchen and arctic entry has yet to be installed, and the upstairs is also open into it, a large portion of our air loss will be eliminated when the arctic entry is finished. The third area we have a major leak is where the plastic folds are not sealed together. These need to be sealed with caulking. We hope that these leaks account for 90% of the air loss, so when they are sealed the air exchanges will decrease from one every four hours to one every twenty hours.

12. Ethylene problems.

The backup heater is an oil-fired space heater. We suspect that it gives off ethylene, for our sunflower developed epinasty after a furnace failure caused the space heater to be used as primary heat for about 3 hours.