Setting Up the Hydro Works Wall-Mounted NFT System

This is the setup guide for the Hydro Works Wall-Mounted NFT System, standard 4-tier configuration.

Your system arrives fabricated. We drill every plant site, cut and fit the inlet and outlet fittings, cap the channel ends, cut the uprights to length and pre-drill them, and supply all the fasteners and wall anchors. You are mounting and commissioning a finished system, not building one — most of the work below is wall work and plumbing.

Prefer not to install it yourself? We install too. Get in touch and we will quote installation with the system.

Specification at a glance

What arrives

Ready-fitted

• 4 × NFT grow channels, 110 mm UPVC, 3 m — each with 14 plant-site holes already cut at 214 mm centres, inlet and outlet fittings and grommets installed, and both ends capped
• 3 × wall uprights, 25 mm square tube, 1.5 m — pre-drilled, with the bracket positions set so the channel fall is correct once they are mounted plumb
• 12 × channel brackets — 3 per channel, including a centre bracket that stops a 3 m channel sagging

Fixings, supplied

• 9 × M8 wall anchor — 3 per upright
• 36 × self-drilling screw — 3 per bracket

Circulation

• 1 × 100 L reservoir
• 1 × Grech HJ1542 submersible pump — 1400 L/h, 28 W
• 5 m × 20 mm LDPE pipe — for the feed riser, the tier-to-tier jumpers and the return

Growing

• 56 × 75 mm net pots
• 1 × Grodan rockwool slab, 50 mm — 100 starter cubes, a full planting of all 56 sites with 44 spare
• 1 × HortiMix nutrient kit
• 1 × pH Up 250 ml, 1 × pH Down 250 ml
• 1 × pH test kit and 4 × pipette

What you need to supply

• Hammer drill with a masonry bit sized for the M8 anchors
• Driver for the self-drilling screws
• A spirit level — 600 mm or longer
• Tape measure and pencil
• Cable and pipe detector
• A sharp knife or pipe cutter for the LDPE, and a bucket

Before you drill: the wall and the clearance

Three checks, all expensive to get wrong once there are holes in the wall.

1. Ceiling height — you need 2.33 m. The system is 1.5 m tall and the balance is working room above the top tier. Without it you cannot lift a mature plant out of its net pot.
2. Masonry wall. The supplied M8 anchors are for brick or concrete. Do not mount this on plasterboard with these fixings — running, the system carries 100 kg of water in the reservoir plus channels, media and crop.
3. Scan for services. Nine holes are going into a wall that will then be permanently damp. Check for cables and pipes first.

Also confirm shade for the reservoir, an RCD-protected socket within reach of the pump lead, and somewhere for water to go when you spill it — because you will.

Step 1 — Mount the three uprights

This is the step that matters most, and the reason is worth understanding.

The channel fall is already built in. The bracket holes in your uprights are positioned so that each channel sits at the correct slope once the uprights are vertical. You never need to set or measure the fall — but that only holds if the uprights go up plumb. An upright that leans tilts the built-in fall with it, on all four channels at once.

1. Mark the three upright positions across the 3 m span: one at each end, one at the centre.
2. Check each mark is plumb with the level before you drill. Spend your time here.
3. Drill for the M8 anchors using the pre-drilled holes in the uprights as your template — 3 anchors per upright.
4. Fit all three uprights loosely, then check once more that each is plumb and that they are parallel and evenly spaced.
5. Tighten fully.

Step 2 — Fit the brackets and hang the channels

1. Fix the brackets to the uprights at the pre-drilled positions, 3 self-drilling screws per bracket. Use the holes provided; they are what set the fall.
2. Work from the bottom tier upward — it is easier than reaching past channels already hung.
3. Seat each channel into its three brackets, making sure it beds fully into the centre bracket as well as the two ends.
4. Check the outlet end of each channel is the lower end, and note which side it falls to. On this system the fall alternates tier by tier so each outlet sits above the next channel's inlet.

Once all four are hung, tip a litre of water down the top channel and watch it run. It should travel steadily end to end and leave no puddles. If it pools, an upright is out of plumb — correct that rather than adjusting the channel.

Step 3 — Reservoir, pump and pipework

1. Place the 100 L reservoir at the base, in shade, on level ground, beneath the outlet end of the bottom channel.
2. Sit the pump flat on the reservoir floor with its inlet clear of the wall.
3. Feed riser: run 20 mm LDPE from the pump up to the inlet fitting of the top channel, and clip it to an upright. An unsupported riser vibrates and works fittings loose.
4. Jumpers: cut short lengths of LDPE linking each channel's outlet to the inlet of the tier below. Keep them short and steep — long shallow jumpers are where blockages start.
5. Return: run the bottom channel's outlet back to the reservoir, finishing above the maximum water line. A submerged return can siphon the tank empty when the pump stops.
6. If the fittings are stiff, warm the LDPE ends in hot water. Do not force cold pipe onto a barb.

About the pump. The HJ1542 is rated 1400 L/h at zero lift, and here it is lifting to 1.5 m, so delivered flow is a fraction of that headline figure — by design, because you only want 1 – 2 litres per minute per channel. The practical consequence: the pump works in the upper part of its head range, so any restriction shows at the top tier first. If tier 1 runs dry, check the pump filter and the riser for kinks before anything else.

Step 4 — Water test, before nutrients

Do not skip this. Fill the reservoir with plain water and run the system for an hour.

1. Check every fitting and joint for weeping. Dry each with a cloth and look again ten minutes later.
2. Confirm a thin film is running the full length of all four channels, not just the top one.
3. Confirm no channel is pooling.
4. Confirm the reservoir level is stable — the return is keeping up with the feed.
5. Switch the pump off and watch. Nothing should siphon, nothing should overflow, and the channels should drain. This rehearses a power cut, and you would much rather find a problem now than with a crop in the channels.

Step 5 — First nutrient charge

Use the supplied HortiMix kit at its stated rate for 100 litres. The order matters:

1. Fill with plain water first. Measure and record its EC — Cape Town municipal water typically starts around 0.2 – 0.4 mS/cm, and that counts toward your target.
2. Add Part A. Stir. Wait until it has dispersed fully.
3. Then add Part B. Stir. Never combine A and B at full concentration in the same jug — they react and precipitate into an insoluble sludge that blocks the pump and is lost to your plants.
4. Circulate 15 minutes before measuring anything.
5. Adjust pH last, to 5.8 – 6.2. Use a pipette and add pH Up or pH Down 2 ml at a time into 100 litres, circulating and re-testing between doses. These are far stronger than people expect, and overshooting will cost you an hour of chasing the number back and forth.

Running numbers

Two things worth adding

Backup power — strongly recommended

NFT holds no water at the root zone. If the pump stops, the film is gone within minutes and the root mat begins drying immediately; on a hot day a crop can be lost in an afternoon. In South Africa that is a scheduled risk, not a hypothetical one.

The system draws only 28 W, which is a very small load — a modest UPS or inverter will carry the pump through a typical outage, and a 12 V solar pump kit removes grid dependence from the circulation loop entirely. Against the value of a full crop, this is the highest-return accessory you can buy.

An air pump and air stone — recommended

Not required: the root mat already breathes air inside the channel. But aeration keeps dissolved oxygen high in the reservoir itself, discourages stagnation, and gives you margin on hot days, when warm water holds less oxygen and root rot organisms are at their most aggressive. On a 100 L reservoir it is cheap insurance.

Reservoir volume — know your margin

At 56 plant sites and 100 L, this system runs about 1.8 litres per plant site. That is a sound working ratio and it sits at the lean end, which has one practical consequence.

A smaller volume per plant means the solution changes faster: every litre the crop drinks measurably concentrates what remains, so EC climbs and pH drifts more quickly than they would in a larger tank. That is not a fault — it just means the routine is not optional:

• Check pH and EC every two to three days, not weekly.
• Keep the reservoir full. A half-empty tank drifts twice as fast.
• Change the solution completely every one to two weeks.
• Keep it cool and shaded. A small tank heats faster than a large one.

Planting out

Seed does not go straight into the channels. Raise seedlings in the supplied 50 mm Grodan cubes and transplant when they have two to three sets of true leaves and visible roots emerging from the plug — usually two to three weeks.

Condition the rockwool before sowing: soak the cubes for several hours in water adjusted to pH 5.5, then drain. New rockwool is alkaline as supplied and will check your seedlings straight from the bag. Do not squeeze the cubes — compressed rockwool loses its air spaces permanently.

The slab holds 100 cubes: a full planting of all 56 sites with 44 spare. Part 5 of the training series covers propagation and transplanting in full.

Grow lettuce first

At 214 mm spacing this system is laid out for lettuce and similar leafy crops, and lettuce is also the most forgiving thing to learn on: fast, tolerant of small pH and EC wobbles, and very clear about when it is unhappy.

Plant one species for your first run — a single reservoir can only sit at one EC, so mixing a light feeder with a hungry one means neither performs and you cannot tell why. And do not fill all 56 sites at once unless you want 56 lettuces in the same week. Sow a small batch every one to two weeks and transplant as sites free up.

Commissioning checklist

1. Ceiling clearance of 2.33 m confirmed, masonry wall, services scanned
2. Three uprights mounted plumb, parallel and evenly spaced
3. Brackets fixed at the pre-drilled positions, centre bracket included
4. All four channels seated, outlets alternating tier to tier
5. Litre-of-water check: runs end to end, no pooling
6. Riser clipped, jumpers short and steep, return above the water line
7. Plain-water test passed — no leaks, film in all four channels, no siphoning on shutdown
8. Source water EC recorded
9. Part A then Part B, circulated 15 minutes
10. pH set to 5.8 – 6.2, EC set for the crop
11. Reservoir shaded, solution under 24 °C
12. Backup power for the pump arranged

Something not behaving as described? Get in touch — send a photo plus your current pH, EC and solution temperature and it is usually quick to diagnose. Part 6 covers ongoing maintenance and a symptom-by-symptom troubleshooting guide.

Learn the method — Basic Hydroponics Training

1. Part 1 — NFT Hydroponics Explained: How the Nutrient Film Technique Works
2. Part 2 — Planning Your NFT System: Space, Water, Power and Crop Choice
3. Part 3 — Assembling a Vertical NFT System: Channels, Slope and Plumbing
4. Part 4 — Commissioning Your NFT System: First Fill, Nutrients, pH and EC
5. Part 5 — Planting Out: From Seed to Channel
6. Part 6 — Weekly Maintenance and Troubleshooting for NFT Systems