Pour the water into a bowl. Mix in the psyllium husk powder, whisking all the time. Let it sit for 2-3 minutes.
Meanwhile, add the sunflower seeds, sesame seeds, pumpkin seeds, flax seeds, chia seeds, and salt to a bowl. Mix well and stir in the psyllium mixture. Lightly grease your hands and continue to mix until thoroughly combined.
Preheat the oven to 180°C (350°F). Line a 30x20cm (12x8 inch) baking tray with parchment paper. Transfer the mixture to the prepared baking tray and spread it as evenly as possible. Bake for 30 minutes.
After 30 minutes, remove from the pan. Using a pizza cutter, cut into 8 equal pieces. Put the crackers back in the oven and bake for another 20-30 minutes or until crisp. If the seeds start burning, reduce the oven temperature.
When done, remove from the oven and cool completely. Break into crackers and serve. Enjoy!
