I live in the Martian wilderness!

As the valve opened, a stream of clear, even slightly warm, groundwater gushed from the pipe onto the bottom of the carbon-sulfur composite plate pool, splashing up sparkling droplets.

Meanwhile, Gu Yu wasn't idle either. He took out a roll of porous silicone tubing from his toolbox and began laying a network of pipes at the bottom of the pool for subsequent aeration.

In just ten minutes, the 5-square-meter running track pool was filled with water, and the water level reached exactly the designed 30 centimeters.

[Water injection complete, total 1.5 tons.]

Gu Yu looked at the shimmering pool water, his heart filled with anticipation.

"Xuan, light it up now!"

"Command confirmed. GZ-05 lighting module, full power startup!"

The lotus root pink light shone again, and the entire running track pool lit up from the inside!

Light penetrated the clear water, turning the entire pool into a giant piece of pink amber.

On the water's surface, light and shadow swayed, like a lake under the moonlight. And on the pool's bottom and walls, the three glowing light sticks were clearly visible, illuminating every inch of the water.

"Perfect……"

Gu Yu was stunned by the vibrant scene before him! Although he was praising it, he was already planning the next work order in his mind.

"Xuan, it's useless just because it looks good. The current running track pool is just an open humidifier."

He picked up the roll of carbon fiber cloth that had been prepared beforehand from the side.

"Now I need to put a lid on this huge bathtub, otherwise this place will turn into a rainforest after the hot water is heated."

He unrolled the seemingly weightless carbon fiber cloth, which, though thin, was incredibly resilient. He covered the edge of the runway pool with it as if laying out a bed sheet.

Gu Yu picked up the induction heating welding gun and began to run the wires along the edge of the pool wall.

The nozzle swept across the edge of the carbon cloth and the sulfur-based interface reserved on the pool wall, instantly melting them and snapping them together like a zipper.

"Sealing test." Gu Yu straightened up and pressed his fingers against the taut fabric. "Very good, it looks like it's very airtight."

Next is temperature control. The pool water is freshly pumped groundwater, and the temperature is only about 20 degrees Celsius.

For spirulina, this temperature is like taking a cold shower; it will curl up and refuse to grow.

The temperature needs to be maintained at 32 degrees Celsius, which is the ideal temperature for spirulina in hot springs.

To keep track of the soup's temperature, Gu Yu pulled out a thermistor sensor, about the size of a fingernail, from his toolbox.

He taped it to a probe and inserted it deep into the center of the pool through the pre-sealed opening.

"Xuan, project the temperature reading onto my HUD. I want to watch it climb up degree by degree."

"Yes, Lieutenant Colonel."

A red number popped up in the bottom right corner of the screen: [20.5℃].

As the two 5-kilowatt heating rods began to output full power, the numbers started to slowly jump.

"Xuan, now we're going to do the final sterilization step. How long do you expect it to take?"

"Reporting to the colonel, according to thermodynamic calculations, it would take approximately 10.5 hours to heat 1.5 tons of water from 20 degrees to 80 degrees."

"Ten and a half hours? Okay, then let it cook on its own, I'm going to sleep."

"Remember to keep an eye on it and don't let the water boil dry. Even though it has a lid, I don't want to wake up in the middle of the night to find my backyard turned into a pressure cooker."

"Monitoring has been initiated, and alarm thresholds have been set. Good night, Lieutenant Colonel."

[Mars Day 15, 07:30 AM]

Gu Yu rushed to the backyard as soon as he woke up. Even through the black carbon cloth cover, he could still feel the sweltering heat.

"Report status".

"The water temperature is 82 degrees Celsius, and this temperature has been maintained for more than 4 hours. The pasteurization and environmental curing processes are complete."

"In theory, all the Earth's microorganisms in the pool walls and pipes have undergone protein denaturation and have been completely eliminated."

"Very good, now pour out this 'bathwater'."

Gu Yu connected the drain pipe, and the water pump roared, pumping the scalding wastewater, rich in dead bacteria and sulfur residue, back into the water treatment system of Oasis No. 1.

Water is innocent, and after filtration, it becomes a clean water source.

Looking at the empty pool that had become clean again, Gu Yu rubbed his hands together.

"Now, let's officially begin filling the tank with water again."

Clear groundwater was injected again, and the liquid level remained steadily at the 30-centimeter mark.

"Start the heating rod." Gu Yu stared at the reading on the HUD. "The target temperature this time is 32 degrees Celsius, which is the temperature that spirulina prefers."

The numbers in the bottom right corner of the screen began to jump slowly.

An hour later, the temperature settled at 32.0℃, and the heating element automatically tripped and entered a low-power pulse heat preservation mode.

"Lieutenant Colonel, the water temperature has reached the required level."

Gu Yu looked at the calm black sheet covering the water. "Now, there's only one last step left—to bring this stagnant pool to life."

If it doesn't move, the light is useless. Once the algal solution becomes concentrated, if it's not stirred, the algae on top will die from the sun, and the algae at the bottom will starve.

"Start the aeration pump, power 20%."

"Buzz—"

A small air pump in the corner emitted a low vibration.

Carbon dioxide gas was forced into the water through the porous silicone tubes laid at the bottom of the pool.

Although he couldn't see through the black cloth, Gu Yu could hear the pleasant "gurgling" sound, the sound of countless tiny bubbles rising in the water.

The buoyancy of the rising bubbles propels 1.5 tons of water to begin flowing slowly along the baffles of the racetrack pool. This creates a stable circulation at 0.3 meters per second.

All the spirulina will be drawn into this cycle, surging from the dark bottom of the pool to the bright lights, where they will photosynthesize for a few seconds before sinking back down to digest the energy.

"Lieutenant Colonel, test complete! Flow rate normal, dissolved oxygen reading normal, temperature locked."

Gu Yu looked at the rows of green data on the HUD and let out a long sigh.

"That's the beauty of industrialized agriculture." There was a hint of pride in his voice. "As long as I don't unplug it, this place is a tireless calorie-producing machine."

[Mars Day 15, 14:30 PM]

In the backyard, by the black running track pool, all the equipment is silently waiting.

The heater maintains the water temperature, the aeration pump drives the water flow, and the light pink glow gently shines on the clear water surface.

"Xuan, although the environment is comfortable, if we put the algae in now, it's like inviting a guest to sit down and drink plain water."

"Although photosynthesis can turn carbon dioxide into sugar, building cell walls, synthesizing proteins, and replicating DNA all require real material raw materials."

"Xuan, generate the recipe proportions for me. I'm going to start 'preparing the nutritious soup'."

"Understood, Lieutenant Colonel. Searching the database..."

"Lieutenant Colonel, considering the need for a closed-loop resource system, we do not recommend using the traditional 'Zaruk' universal culture medium. That formula is based on the premise that there is an abundance of industrial fertilizers on Earth."

"You have been switched to the [Lunar Palace-III Type Space Microalgae Circulation Culture Medium]."

Xuanjian projected a detailed document onto the screen, bearing the heading of the Environmental Biology and Life Support Technology Laboratory of Beijing University of Aeronautics and Astronautics.

"This formula originated from the closed-loop experiment of China's 'Lunar Palace-1' in the early 21st century and has been verified in orbit on the Tiangong space station for ten years."

"It is specifically designed for the 'human-algae-waste cycle' system."

"Its core advantage lies in the fact that it greatly improves spirulina's tolerance and absorption rate of urea nitrogen, making it a perfect fit for our current waste recycling system."

Upon hearing this familiar name, Gu Yu's lips curled up slightly: "Lunar Palace One... Okay, let's use this formula."