Ebb & Flow Trays
Ebb and flow trays, also called flood and drain tables, hold your pots while a pump floods the base on a timer. The solution then drains back to the reservoir, pulling fresh oxygen to the roots. Hydroponics UK stocks 13 G-Tools trays and fittings. Prices run from £59 for a 0.52 by 0.52 m tray to £382 for a 2 by 1 m flood table. Each tray has integrated gutters that channel runoff to a single deep drainage point.
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Ebb and Flow Trays: How Flood-and-Drain Hydroponics Feeds Your Roots
An ebb and flow tray is the bed of a flood-and-drain hydroponic system. A pump fills the tray with nutrient solution on a timer. Roots draw food and water directly through holes in the pot base. The pump then switches off and the solution drains back to the reservoir below. As the level drops, fresh air is pulled into the growing medium. This wet-dry cycle builds strong, oxygen-rich roots with very little daily input from you.
Choosing a tray starts with your grow space. Match the tray footprint to your bench, rack tier or grow box, then pick fittings to suit your method. A flood-and-drain setup needs an inlet and an overflow. A drip setup needs only one drainage outlet. Every G-Tools tray is moulded from UV-resistant virgin plastic, so high-intensity lighting will not make it brittle. The trays ship without lead-throughs, so you fit valves and outlets sized to your own system.
Comparing the G-Tools Tray Sizes We Stock
The four main trays cover most home and small commercial setups. Smaller trays suit propagation and single grow boxes. The larger flood tables fill a full rack tier. The table below compares footprint, ideal use and price so you can size up quickly.
| Tray | Best for | Dimensions | Use | Price |
|---|---|---|---|---|
| Tray 0.52 by 0.52 m | Propagation, single grow box | 520 by 520 mm | Flood-and-drain or drip | £59 |
| Tray 1.1 by 0.63 m (Matt's Pick) | Bonanza 1 m² grow box | 1,100 by 630 mm | Flood-and-drain or drip | £62 |
| Tray 1.1 by 1 m | Wider single-tier benches | 1,100 by 1,000 mm | Flood-and-drain or drip | £73 |
| Tray 2 by 1 m | Full rack tiers, production | 2,000 by 1,000 mm | Flood-and-drain or drip | £382 |
Matt's Pick: Tray 1.1 by 0.63 m
Best for: a complete 1 m² grow box or single bench
Why we rate it: the 1,100 by 630 mm footprint drops straight into the Bonanza 1 m² grow box. The gutters drain to one deep point, and standard PVC couplings fit without proprietary parts.
Price: £62
How to Set Up Valves, Siphons and Overflow on Your Tray
Every tray drains to a single deep point that takes standard PVC push-fit couplings. For a basic feed and drain, fit a 3/4 inch tray valve as the bulkhead. Run your pump line into it. Add a second lead-through set above your flood line as an overflow. That overflow is the simplest safeguard against a stuck pump float waterlogging your roots overnight. Keep flood depth below the rim of your pots. Aim for 40 to 50 mm with most 6 to 11 litre pots.
For automatic, pump-free cycling, a siphon valve does the work without a timer on the drain side. The passive 3/4 inch siphon valve sets three water levels and drains the tray quickly once it fills. A complete system also needs a reservoir, a feed pump and a timer. Pair the tray with our irrigation kits and a grow rack for a tidy, multi-tier setup. Most growers run two to four flood cycles a day under lights.
We stock G-Tools because the trays are sized to real grow boxes and tables, not just sold loose. Buying the tray with its matching aluminium grow table gives you a level, watertight bed. It holds many pots without flexing. Fit the overflow before you ever trust a timer. I have seen one stuck float flood a whole room, and a five-pound overflow fitting prevents it every time.
- Matt W, Hydroponics UK
Frequently asked questions
It is the bed of a flood-and-drain hydroponic system. A pump floods the tray on a timer. It then drains back to the reservoir, pulling fresh oxygen to the roots.
Match the tray footprint to your bench or grow box. A 0.52 by 0.52 m tray suits propagation. A 2 by 1 m flood table fills a full rack tier for production.
No, every tray ships without lead-throughs. This lets you spec inlet, outlet and overflow fittings to match flood-and-drain or drip. Standard 3/4 inch PVC couplings fit the drainage point.
Keep the flood below the rim of your pots. A depth of 40 to 50 mm suits most 6 to 11 litre pots. Flooding too deep starves the upper root zone of oxygen.
Run two to four flood cycles a day under lights. Reduce the frequency during the dark period. Increase it as plants mature and the growing medium dries out faster.
No, the trays are moulded from UV-resistant virgin plastic. Ordinary plastics go brittle under high-intensity lighting. This material holds up to years of use in a controlled grow room.
Build a full system around your tray. Pair it with grow tables for a level base and grow racks for multi-tier growing. Add the right grow lights to drive healthy growth.