13mm IWS Fittings — Genuine Hydroponic System Components for Flood and Drain Setup
Best for: IWS system owners needing spares, growers scaling their setup, and DIY hydroponic builders who want proven components that actually fit properly
Our thoughts
If you're running an IWS system or building something custom, you need fittings that seal tight and don't leak all over your grow space. These are the genuine parts — barbed, reliable, and designed to work with 13mm flexi-pipe. One we recommend for anyone who's had to bodge a connection with generic bits.
13mm IWS fittings are genuine hydroponic system components designed to connect, redirect, and control nutrient solution flow in flood and drain setups. Whether you're replacing damaged piping, extending your system, or building a custom hydroponic solution from scratch, these barbed fittings create secure, water-tight connections with 13mm flexi-pipe (16mm outer diameter). The range includes universal tees, straight connectors, elbows, anti-siphon valves, and specialist inserts — everything you need to keep your system running leak-free.
How it compares
IWS fittings sit at the premium end of the 13mm barbed fitting market because they're designed specifically for proven hydroponic systems, not generic plumbing.
- Genuine IWS parts with 20-year brand heritage in UK hydroponics
- Better fit tolerance than cheap generic barbed fittings — less leaking, less bodging
- Compatible with IWS systems, RTA, Multiflow, and DIY custom builds
- Specialist options (anti-siphon valves, copper root control inserts) that generic ranges don't offer
- UK-manufactured with proper support if something goes wrong
In plain terms: you're buying compatibility and peace of mind, not just plastic bits.
Usage guidance
IWS fittings are dead simple to install once you know the method:
Basic installation
Cut your 13mm flexi-pipe to length using pipe cutters or sharp scissors. Warm the cut end in hot water for 10-15 seconds to soften it, then push the fitting barb in firmly. Insert the fitted end into your sealing gland and tighten down. Tighten hose clips around the connection to guarantee a water-tight seal.
Connecting the system
Use straight pieces to link the brain-pot to outer-pots. Deploy tees and elbows to split flows and change direction without kinking or restricting the pipe. The swivel elbow is especially useful if you need to route pipework around obstacles without bending or pinching the line.
Anti-siphon valve setup
Fit an anti-siphon valve at the end of longer piping runs to stop water flowing backwards once your pump shuts off. This prevents air locks and ensures every plant gets the full programmed feed, every time.
Root clogging prevention
If you're running in a system where roots can reach the irrigation pipes (common in larger setups), fit a copper root control insert into your sealing gland. Copper naturally repels root growth and keeps your lines clear without chemicals.
Scaling and customisation
The IWS system is fully modular. Add pots, remove pots, rearrange them — the fittings stay the same. This is why growers favour IWS for long-term setups. Buy the fittings as you expand.
Technical specifications
- Pipe size: 13mm barbed (16mm outer diameter flexi-pipe)
- Sealing gland hole size: 25mm
- Material: Durable plastic (barbed fittings), copper (root control inserts)
- Fitting types available: Universal tee, straight connector, universal elbow, swivel elbow, female hose tail barred, anti-siphon valve, copper root control insert
- Installation: Barbed end into heated pipe, smooth end into sealing gland
- Recommended accessories: Hose clips for leak prevention
- Compatible systems: IWS standard systems, RTA, Multiflow, DIY custom builds
Who this is for
- Existing IWS system owners replacing lost, damaged, or worn fittings
- Growers scaling up their IWS setup with additional outer-pots
- DIY hydroponic builders who want proven components with proper fit tolerance
- Commercial or semi-professional growers building custom flood and drain solutions
- Anyone tired of cheap generic fittings that leak and need constant re-sealing
Particularly valuable if you're scaling a system over time or maintaining one that's running 24/7 — genuine parts mean fewer leaks and less downtime.
Our take
These are proper hydroponic fittings from a brand that's been building reliable watering systems for 20 years. You're not paying for the name — you're paying for fit tolerance, compatibility, and specialist options that a generic barbed fitting simply doesn't offer.
If you've got an IWS system or you're building something custom and want fittings that seal tight first time, worth picking up. Better yet, buy them before you need them in an emergency. Good time to grab spares while stock lasts.
