If they wanted to solve the egg problem at the root, for now only filtration systems could remove the eggs. The awkward part was that all the equipment had been flooded.
Before the apocalypse, this would not have been a problem. They could have rushed out a batch of ultrafiltration units. In America, every household drank straight from the tap because the factories filtered it in advance. Over there this would not even count as a problem.
Now, producing these units was nearly impossible, especially the precision components. Raw materials were hard to find. Even the unit and the filter cartridges were not made in the same place. A single device required hundreds or even thousands of kinds of materials.
So the only option was to salvage pre-disaster equipment.
But there were only so many units to go around. Too many monks, too little porridge. At first, people could drink water full of eggs without obvious issues. Soon, when the eggs evolved, that water would mean constant stomach pain, diarrhea, even dehydration. Before, at least poops landed in solid piles. Soon, the streets would be smeared with puddles. Ugh. The news said it was a reaction between bacteria and the gut, like food poisoning.
At that point ultrafiltration, or even plain bottled water, would become priceless. Those with access would live comfortably. Those without would grit their teeth and endure.
Still, the clever kept experimenting. Bit by bit, people found ways to filter out some of the eggs.
"Mom, if a filtration system can remove eggs, then our ancestors' methods can remove eggs too," Jing Shu said lazily.
"What method? We cannot install our household filter at work, and the trickle we filter at home is nowhere near enough to irrigate all those vegetables.
You mean something else? We have already tried wilderness survival filters, but they do not remove the eggs cleanly. Researchers say the eggs are like invisible bacteria. Can anything that tiny be filtered out?"
Beyond ultrafiltration, people were desperate for something that actually killed eggs. Zhu Chuangshi's solution had turned him into a national celebrity, interviewed by TV and invited everywhere to remove eggs, but his method did not cure the root and was hard to scale.
There were also attempts at ultraviolet disinfection and chemical disinfection. Those knocked down part of the load, but the remaining eggs still kept seeds from sprouting.
"Come on. Let's go up the back hill for materials. I will try something at your department tomorrow," Jing Shu said mysteriously.
Su Lanzhi was skeptical. With technology this advanced, what could an ancient method do? It certainly would not meet drinking-water standards.
It did not need to. As long as the water could be used to grow crops, it would do.
Jing Shu dragged Su Lanzhi up the back hill for an afternoon of rummaging. They collected all kinds of minerals and stones, even yellow clay.
They hauled home a full cart. At four in the morning, Su Lanzhi, itching to try, yanked Jing Shu out of bed for work.
First, at the faucet, Jing Shu wrapped soil in layers of cloth, stacked in large, medium, and small particle sizes. Water seeped down through the three stages, trapping red nematodes and their eggs outside. The soil bundle had to be replaced daily.
Then Jing Shu spent the whole day building a super-sized pool.
Water that passed the first stage flowed into a pool shaped like the character "凹".
The first compartment held big rocks, large pebbles, small pebbles, rubble, fine sand, and yellow clay. After sedimentation, the water entered the second brick compartment filled with charcoal and fine sand.
Su Lanzhi hesitated. They had tried something like this before, and the results had not been great.
Still, that brought the water through basic filtration. The third compartment was a large storage pool. At the top was a wooden stopper. Once full, water wicked through the wood and overflowed into four small basins, passing a second round of filtration.
Most households could stop at the third pool and remove a significant share of eggs. The fourth step was not busywork. It was waiting for the eggs in the third pool to grow.
The smallest known bacteria are larger than 0.1 micrometers, and within two or three days the eggs would swell to that scale. If they could not filter them today, they would wait until the eggs grew a bit, then filter. Some suggested skipping straight to filtering adult red nematodes and letting old nematodes eat the larger eggs. That worked, but it was painfully slow. Here, releasing old nematodes was only for cleanup.
"Every day we need to catch old nematodes and release them into the third and fourth pools to clean up the eggs that have grown," Jing Shu said.
There would still be escapees in the fourth basin, but they could lay out sheets of vegetable roots on the surface. Half the eggs would gather there. Once they grew, the old nematodes could eat them.
It was pig-farming logic. Let them grow, then harvest.
A drain hole opened in the middle of the fourth basin. The final outflow ran into a fifth compartment.
With the hole in the middle, sediment settled at the bottom, eggs gathered on the vegetable leaves up top, and the water in the middle was the filtered fraction, basically clean enough for growing vegetables.
This tiered filtration existed as early as the Chongzhen era in the Ming dynasty. In the previous life, someone improved it and found that the "凹"-shaped chain truly worked. One stage fed the next, links interlocked. It was more efficient than a single filter.
"Mom, the downside is that filtration is slow. One pool of water will take about a day. But one pool should be enough for your irrigation, right?"
"Enough, enough. My girl may not have been great at exams, but everything else she does is marvelous."
After Jing Shu taught Su Lanzhi the principle, the department finally stopped running dry for several days.
They began planting a new batch of vegetables. Jing Shu had a feeling Su Lanzhi would set a strong example for Wu City this time.
While the other twelve departments stuck to raising simple mushrooms, only Su Lanzhi's Development Zone used this old-school filtration to get usable water and still managed to grow crops. Slower, yes, but undeniably a major contribution.
As for ordinary people's food, there had been a small improvement lately.
The government could not grow many other crops, but water was abundant, so the first batch of mushrooms came out, all covered with eggs.
They looked terrifying.
Layer upon layer of mushrooms were speckled white with eggs, like blackheads dotting a face. After the canteen aunties boiled them, they tasted bouncy. Bite down and they popped like fish roe.
Mushrooms boiled with eggs, 0.2 coins a serving. Add a ladle of batter, 0.5 coins.
But if you voted on the big data app for Zhao Shupi to become Distribution Director, you got an extra ladle of batter for free.
In no time, Zhao Shupi became a sensation in Banana Community, racking up support. Lines formed at the batter window. Cast a vote, get a ladle.
That very day, Wang Qiqi brought Jing Shu 500 coins borrowed from all over. "How do I maximize the benefit of 500 coins?"