Plain-language guides covering everything from the nitrogen cycle to advanced water chemistry. Start at the beginning or dive into the specific topic you need.
Start from the beginning — what aquaponics is, how the nitrogen cycle works, and how to choose your first system. No experience required, no jargon, no skipped steps.
Start at the beginning →Skip the basics. Dive into advanced water chemistry, stocking ratios, seasonal management, system optimization, or troubleshoot something specific that's not working.
Go deeper →Understanding the nitrogen cycle is the single most important thing you can learn about aquaponics. Every problem, every success, every maintenance decision connects back to this.
The nitrifying bacteria that convert ammonia to nitrate are what make aquaponics work. They colonize every surface in your grow bed — clay pebbles, pipes, tank walls. A mature system has billions of them. Without them, you just have an expensive fish tank.
The bacteria that process nitrites (Nitrobacter) reproduce slowly — roughly one generation every 24 hours. You can't rush a new system. The good news: once your system is cycled, it stays cycled as long as you keep feeding the fish and don't crash the bacteria with chlorine.
A cycled system should read: ammonia <0.25 ppm, nitrite <0.5 ppm, nitrate 20–80 ppm, pH 6.8–7.2. If your ammonia or nitrite is elevated, something's wrong. The troubleshooting guide covers every scenario.
Each system type moves water differently. The right choice depends on what you want to grow, your budget, and how much space you have.
Fish tank water floods the grow bed on a timer, then drains through a bell siphon. The grow bed is filled with clay pebbles or gravel. Simple, forgiving, and the best choice for beginners.
Best for: All vegetables, herbs, and fruiting plants. Works with any fish species.
Plants float on foam rafts with roots suspended directly in nutrient-rich water. Water flows continuously from the fish tank through long channels under the rafts. Extremely fast growth for leafy greens and herbs.
Best for: Lettuce, basil, spinach, kale. Poor choice for fruiting plants or root vegetables.
A thin film of nutrient-rich water flows continuously along the bottom of sloped channels. Plant roots trail down the channel and absorb water and nutrients as it passes. Very water-efficient and scalable.
Best for: Strawberries, herbs, and greens in commercial or semi-commercial setups.
Water testing is the closest thing to a check engine light your system has. These are the four parameters every aquaponics grower monitors.
The most important number. Produced by fish waste and uneaten food. High ammonia (above 1 ppm) stresses fish; above 2 ppm can be lethal within hours. Test daily during cycling, weekly in a mature system.
The intermediate product in the cycle — more toxic than ammonia to fish at equivalent concentrations. High nitrite (above 1 ppm) causes "brown blood disease" in fish. Nitrite spikes are common during cycling and after adding new fish.
Plant fertilizer — the end product of the nitrogen cycle. Harmless to fish at low levels (below 150 ppm), and exactly what your plants need to grow. High nitrate means your plants aren't keeping up — add more plants or reduce fish stocking.
The sweet spot where fish thrive, bacteria work efficiently, and plants absorb nutrients optimally. pH affects every other water parameter. Most problems with pH rising are caused by calcite-based media like limestone gravel — use Hydroton instead.
Each topic page gathers everything on that subject — articles, guides, and product recommendations in one place.
The most important beginner articles — read these before you build anything.
Articles are being written now. Check the Education archive →
Once you understand the basics, the next step is picking a system size and build plan. We've done all the math — choose a plan that fits your space and budget.
Browse Free Build Plans → Troubleshoot Your System