Gaza Strip - January is usually a busy month for farmers in Gaza, as it marks the wheat planting season, but so far, Jaber Abu Rejela has had little work to do on his 80 dunams (8 hectares) of land in Abasan al-Kabira, near the Israeli border.

"I have nothing to do. I'm looking for ways out of this country because we have nothing else to do," Abu Rejela, 57, said wryly, noting that he was waiting for Israeli forces to spray pesticides over his farmland before planting, as the crops would be ruined if they were sprayed afterwards. The Red Cross told farmers that Israel would spray pesticides from mid-December to mid-January.

According to Adham Bassiouni, chairman of Gaza's Integrated Pest Management, most of the crops in more than 4,000 dunams of land near the border were damaged last year due to sprayed pesticides.

Gaza's most arable land is also its most dangerous. More than a third of Gaza's agricultural land is now part of the Israeli buffer zone.

Abu Rejela's family has been farming for generations, but it has never been as difficult as it is now. Israeli forces have shot at farmers on their land near the buffer zone, and due to power outages, the irrigation system cannot properly water the crops, Abu Rejela explained.

With shrinking cultivable land and the water system largely contaminated, many Palestinians in the impoverished Gaza Strip have been searching for alternative ways of finding fresh food and water.

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At sunset on a warm January day, Said Salim Abu Nasser's three grandsons crouched on the ground, using bricks to crush chalk into powder for calcium to help grow vegetables in water.

Abu Nasser, 53, has grown 3,500 kilogrammes of organic produce without any soil, transforming his rooftop and concrete lot in Gaza City into an organic oasis. He grows a dozen different types of vegetables and herbs for his family, including eight children and eight grandchildren.

Using hydroponic techniques, Abu Nasser can grow twice as many crops than with conventional techniques, and he saves 90 percent more water by recycling nutrient-dense water. His broccoli, tomatoes, lettuce and cauliflower float on polystyrene squares with holes cut into them, while their roots absorb nutrients from the water.

"For six months, I don't need to change the water," Abu Nasser said.

When the power is out, his solar panels produce enough energy, even in winter, for his pipes to pump oxygen into the water for his crops.

On his rooftop, he grows herbs, lettuce and peppers with aquaponic farming. The water, containing excrement from fish swimming in a barrel, is used as a vital nutrient to grow produce.

"We previously thought that it would be impossible to grow anything in high-salinity water, but after [Abu Nasser's experiments], we found out that we can," said Mahmoud Jawad al-Ajouz, a professor of agriculture at Gaza's Al-Azhar University.

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A carpenter by day, Abu Nasser received a grant and basic training from the United Nations Food and Agriculture Organization to start up his hydroponic micro-farm.

"When I first started farming, I only encountered problems. After 15 days, my plant would die," Abu Nasser said.

Hydroponic farming is not an easy task; the water typically requires a mix of 16 different elements for the crops to grow successfully. After constant experimenting and following research from Al-Azhar University, Abu Nasser learned all the right tricks.

Mineral fertilisers are expensive to buy in Gaza, so as an alternative, he has learned to mix dried, crushed eggshells with ash in the water as a source of calcium, potassium and phosphor. The chalk that his grandchildren help to grind is also used as a cheaper, alternative source of calcium

"Every home must have a farm," Abu Nasser said. "Farmers are only thinking of how they can make money; they spray too many pesticides, chemicals and fertilisers on their crops, which affects the food, the land and the water … We are working for future generations so they can, in turn, grow their own healthy food."

Iyad al-Attar, from Beit Lahiya in northern Gaza, also received a UN grant to launch a hydroponic project after his family's rented farmland was bulldozed and annexed as part of Israel's buffer zone.

He spent years cultivating fish for his backyard aquaponic farm. After many costly experiments, he now grows 5,000 lettuce heads a year on water, along with a dozen other crops. To prevent crop diseases, he uses solutions mixed with natural ingredients, such as onions, hot peppers and olives, instead of chemicals.

"The most precious thing is the health of a human being," Attar said. "The situation in Gaza pushed me to pursue this project. There are too many buildings, the land is shrinking and clean water is scarce."

His farm was damaged during the Israeli war on Gaza in 2012 and completely destroyed in 2014, when an Israeli drone hit the generator. He previously employed 10 people, but now runs the facility himself, after having it rebuilt.

Today, 96 percent of Gaza's water is unfit for human consumption after decades of over-pumping from its aquifer, which has lowered the groundwater level and allowed seawater to seep in.

Last year, Gaza photographer Fayez al-Hindi created his own water distillation and purification system using solar energy. Tap water is poured into a three-metre-long basin, and as it evaporates onto the panels, it purifies and the clean water drops into a separate basin.

On an average sunny day in winter, his invention produces four to six litres of clean drinking water for his family.

"As human beings, we cannot live without water; we depend on water every day," Hindi told Al Jazeera. "But the cost of water filters is expensive and the economic situation is bad, so I was thinking of alternative ways to filter the poisoned water and to share it with people."

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Lab technician Mohammed Abu Shamaleh, from the Coastal Municipalities Water Utility, tested Hindi's water and found the results to be astonishing.

"Older generations have used distillation, but the thing is, it needs electricity and fuel ... It's expensive. However, Fayez's technique uses only solar power, and it's free. The water he gets is pure, without any salt," Abu Shamaleh said, noting that the technique "solves a lot of problems, especially here in Gaza, since we face a lot of obstacles to get clean water".

Unfortunately, Hindi says that he has found little support to expand his project.

"It cost less than $1,000 to put together. For a cheap price, all Gaza residents can drink their own clean water," he said. "But many families still can't afford it."