5 Hydroponic Systems You Can Build with Items from the Pound Shop

#1The Food Container Kratky (£3) — Cheapest & Simplest

The absolute simplest hydroponic system. One container, one plant, zero moving parts, zero electricity, zero maintenance beyond a weekly glance.

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Assembly

Cut a hole in the centre of the lid, slightly smaller than your sponge cube so it fits snugly without falling through. If you have net pots from Amazon UK (approximately 50p each in bulk packs), use those instead of a sponge for a cleaner fit.

If the container is transparent or translucent, wrap it completely in aluminium foil to block light. Any light reaching the nutrient solution causes algae, which competes with your plant for nutrients.

Fill the container with nutrient solution mixed at half strength, leaving approximately 1 centimetre of space below the lid. Place a pre-germinated seedling (lettuce, basil, or any small herb) into the sponge cube. Set the sponge into the lid hole so it touches the nutrient solution below. Snap the lid on.

Place on a sunny windowsill and leave it alone. Check the water level once a week. As the plant drinks, the water drops and an air gap forms — this is intentional and provides oxygen to the roots. Do not refill to the original level. That is genuinely the entire process.

Best for: Absolute beginners who want to prove to themselves that hydroponics works before investing any significant money. This £3 system grows lettuce in 30-45 days and herbs in 21-35 days.

#2The Yoghurt Pot Herb Garden (£4) — Most Variety

A collection of individual small containers, each growing one herb, grouped together on a tray for a mini kitchen garden effect.

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Assembly

Wrap each yoghurt pot completely in aluminium foil. Cut a hole in the base of each pot (approximately 1cm diameter) and thread a small piece of sponge or cotton wool through as a wick. This draws water upward from the tray below.

Place all pots on the tray. Pour nutrient solution into the tray to a depth of about 2 centimetres. The wicks will draw the solution up into each pot. Place a sponge cube with a seedling in the top of each pot. Cover the tops loosely with cling film until seeds germinate to retain moisture and warmth.

Each pot grows one herb plant. With six pots you can have basil, mint, coriander, parsley, chives, and lettuce all growing simultaneously in a space no larger than an A4 sheet of paper. Top up the tray with nutrient solution every 3-5 days as it is absorbed.

Best for: People who want variety from day one. The individual pots let you grow 4-6 different herbs using materials that would otherwise go in the recycling bin. Total growing area: one small kitchen tray.

#3The Storage Tub Multi-Plant Kratky (£5-6) — Best Value per Plant

A single larger container growing 4-6 plants simultaneously from one shared reservoir. This is the most productive budget hydroponic system per pound spent.

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Assembly

Mark 4-6 evenly spaced circles on the lid, each approximately 5 centimetres in diameter. Space them at least 10 centimetres apart so the plants have room to grow without crowding each other. Cut the holes carefully using a sharp knife or scissors.

Fill the tub with nutrient solution mixed at the appropriate strength for your crops (half strength for seedlings, full strength for established plants). Insert sponge cubes or net pots with seedlings into each hole. Snap the lid onto the tub firmly.

This is a multi-plant Kratky system. All plants share the same reservoir, which has two important implications. First, the larger water volume means pH and temperature are more stable than in individual jars, which is an advantage. Second, all plants receive the same nutrient concentration, so you should group plants with similar needs. Grow all lettuce, all herbs, or all leafy greens in one tub. Do not mix leafy greens (which need low EC) with fruiting crops (which need high EC). See our nutrient schedule guide for EC targets.

A 20-litre tub growing 6 lettuce plants produces enough salad greens for a family of four, harvesting 1-2 heads per week on a staggered cycle.

Best for: Growers who want maximum production from a single container. The shared reservoir means less maintenance (one pH check covers all plants) and the dark storage box blocks light without needing foil. This is arguably the best value budget hydroponic system available.

#4The Washing-Up Bowl DWC (£7-8) — Fastest Growth

A step up from passive Kratky: this system adds an air pump for faster, more vigorous growth. It is still extremely budget-friendly and grows noticeably faster than passive systems.

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Assembly

Place the air stone in the bottom of the bowl, connected to the air pump via the included airline tubing. Fill the bowl with nutrient solution to approximately 3 centimetres below the rim.

Create a lid from your chosen material. Thick cardboard works for short-term use (it will eventually absorb moisture, so cover it in cling film or foil to extend its life). A piece of polystyrene packaging is better — it is waterproof, lightweight, and floats if it drops into the water. A plastic chopping board cut to size is the most durable option.

Cut 2-3 holes in the lid for sponge cubes or net pots. Insert seedlings, place the lid on the bowl, and turn on the air pump. The continuous bubbling oxygenates the solution, promoting faster root development and more vigorous growth compared to passive Kratky systems.

Position near a window or under a grow light. The air pump runs 24/7 but uses less electricity than a phone charger. Place it on a folded towel to minimise vibration noise.

Best for: Growers who want faster results than Kratky provides but are not ready to invest in a full bucket system. The washing-up bowl is wide and shallow, which makes it excellent for growing a cluster of lettuce heads that need horizontal space rather than deep roots.

#5The Vertical Bottle Tower (£5) — Most Impressive Visual

The most visually impressive budget hydroponic system. A vertical stack of recycled bottles grows 4-8 plants in the footprint of a single bottle. This is perfect for growers with very limited horizontal space but a wall, railing, or hook to hang from.

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Assembly

Cut each bottle in half horizontally. In the bottom half of each bottle, cut a planting hole approximately 5 centimetres wide in the side, about 3 centimetres from the cut edge. This is where the plant will emerge.

Poke 2-3 small drainage holes in the bottom of each bottle half. Thread strong string or garden wire through these holes to connect the bottles vertically, with each bottle half sitting above the next like a chain. Space them about 15-20 centimetres apart on the string.

Wrap each bottle half in aluminium foil. Fill each one with a growing medium: cotton wool, perlite, coconut coir, or even shredded newspaper work. Plant one seedling per bottle through each side hole.

Hang the tower near a bright window, from a balcony railing, or on a wall hook. When you water (by pouring nutrient solution into the top bottle), it trickles down through each bottle in the chain, watering each plant on its way down. Excess drains from the bottom into a catch tray.

This system works best with lightweight crops: herbs, small lettuce varieties, strawberry plants, and microgreens. Avoid heavy fruiting crops that would weigh down the tower. See our vertical hydroponic tower guide for more elaborate vertical builds.

Best for: Apartment growers with limited counter or windowsill space who have a wall, window frame, or balcony railing available for hanging. The tower grows 4-8 plants in a vertical strip approximately 15 centimetres wide. It is also an excellent conversation piece and science project.