AutoPot vs DWC vs NFT: Which Hydroponic System Is Cheapest to Run in Australia?

Chris Brubeck. Reviewed August 2026.

If you already read our guide to hydroponic power usage and running costs, you will know that light and fan wattage dominate the electricity side of any setup. What that guide does not cover is how the hydroponic system itself, not just the light, changes your running cost once you factor in nutrient and medium across a full cycle. That is what this guide sets out to answer, using AutoPot, Oxypot DWC and Gro-Tank NFT as the three systems, since between them they cover the three different approaches to feeding a plant hydroponically, no pump at all, a static oxygenated reservoir, and continuous recirculation.

How We Worked Out the Running Cost

To keep this a fair comparison, all three systems are calculated using the exact same tent, light and fans, so the only variable that changes is the system itself. The setup used across all three is a HOMEbox Ambient R120S tent, an Osram NAV-T 250W HPS lamp run through a JBL Digital Ballast switched to 250W with a JB Bat Wing Reflector, an Air Mixed Flow Fan at 100mm for extraction, and a Heller Clip Fan for canopy circulation.

We used a 16 week cycle (close to 4 months) and a blended average of 15 hours of light per day across the cycle, since most fruiting crops run an 18 hour vegetative stage followed by a 12 hour flowering stage, and 15 hours is roughly what that averages out to. Electricity is costed at Victoria's current rate of 25.5c per kWh, the same rate used in our running costs guide. Nutrient is costed at an estimated $0.20 per litre of mixed feeding solution, a reasonable mid range figure for a quality 2-part nutrient at label dose. Reservoir change frequency is taken directly from Apex Grow's own product guidance, every 7 to 14 days, and we have used 10 days consistently across all three recirculating systems rather than mixing in figures from other sources, so the comparison stays like for like. Plant count is 1 for the Oxypot single, 2 for the AutoPot Hydropak starter kit, and an estimated 6 for the Gro-Tank 424, based on typical net pot spacing along its 112cm channel, since Apex Grow does not publish an exact site count. Fan and pump wattage for the Heller Clip Fan is a confirmed 15W. The 100mm inline fan is not published by the manufacturer, so we have used 25W, in line with comparable fans of the same size and type. The Oxypot's included air pump and the Gro-Tank's included water pump are not individually specified either, so we have used typical figures for pumps of that scale, 4W for the air pump and 20W for the water pump. Where a figure is an estimate rather than a published spec, we have said so.

AutoPot Hydropak Running Cost

The AutoPot Hydropak Starter Kit uses a gravity fed Smart Valve, so there is no pump and no electricity used for irrigation. The only power draw across the whole cycle is the shared light and fans.

Electricity: 562.8 kWh across the cycle, all of it light and fans, none of it irrigation. At 25.5c per kWh that comes to $143.52.

Nutrient: the 35L reservoir typically lasts 3 to 5 weeks per fill going by AutoPot's own specification, so over a 16 week cycle that works out to around 4 refills, 140L of mixed solution total across the 2 plant sites in the starter kit, around 70L per plant. For a nutrient built for exactly this use case, Byron Bay Gold's 3-stage system is what our own nutrients guide points to for AutoPot style fruiting crops like tomatoes and capsicum, starting from $38.95 per stage.

Medium: the perlite and vermiculite mix is included in the starter kit, so there is no separate first cycle cost. It can be rinsed and reused for a following cycle, though most growers replace it fresh for a new crop.

Total running cost per cycle: approximately $171.52, or around $85.76 per plant.

Oxypot DWC Running Cost

The Oxypot DWC system comes with its air pump included, and it needs to run continuously, the roots depend on it for oxygen.

Electricity: the air pump adds only 10.75 kWh across the whole cycle on top of the shared 562.8 kWh from light and fans, for a total of 573.55 kWh. At 25.5c per kWh that is $146.26.

Nutrient: the 19L single Oxypot reservoir changes every 7 to 14 days, the same interval as the Gro-Tank. Over 16 weeks at a 10 day average that is around 11 changes, 212.8L of mixed solution. Since the single Oxypot only holds one plant, that entire 212.8L is going to one plant, making it the least nutrient efficient of the three per plant. At $0.20 per litre the nutrient cost is $42.56. For the nutrient itself, GT Optimum Grow & Bloom is built specifically for DWC and NFT recirculating systems, with pH-stabilising technology to hold reservoir pH steady between changes, from $64.95 for 1L.

Medium: clay pebbles, and only a small amount per plant. A 50L bag of LECA clay balls at $19.95 will last many cycles, since the pebbles just get rinsed and reused rather than replaced.

Total running cost per cycle: approximately $188.82, all of it feeding a single plant.

Gro-Tank NFT Running Cost

The Gro-Tank NFT system ships with a matched pump, and like the Oxypot, it runs continuously. NFT depends on constant flow across the roots, there is no reservoir the roots sit in permanently.

Electricity: the pump adds 53.76 kWh across the cycle on top of the shared 562.8 kWh, for a total of 616.56 kWh. At 25.5c per kWh that is $157.23.

Nutrient: the 45L tank changes every 7 to 14 days, the same interval as the Oxypot. Over 16 weeks at a 10 day average that is around 11 changes, 504L of mixed solution. The 424 size tank fits roughly 6 plant sites along its channel, so that 504L is feeding 6 plants rather than 1, around 84L per plant, close to what AutoPot achieves and far ahead of the single plant Oxypot. At $0.20 per litre the nutrient cost is $100.80. The same GT Optimum Grow & Bloom suits NFT for the same reason it suits DWC, listed as compatible with continuous recirculating systems rather than a standard 2-part built for run to waste use, from $64.95 for 1L.

Medium: none required for the tank itself. You do need net pots to hold each plant, around 8 for the 424 size tank using LP-50 net cups at $6.95 each. That is a one off cost of around $55.60, and the net pots are reused every cycle after that.

Total running cost per cycle: approximately $258.03, spread across roughly 6 plants, around $43 per plant.

Running Cost Compared

AutoPot: $143.52 electricity / $28.00 nutrient / $171.52 total per cycle / roughly $86 per plant

Oxypot DWC: $146.26 electricity / $42.56 nutrient / $188.82 total per cycle / $188.82 per plant, since there is only one

Gro-Tank NFT: $157.23 electricity / $100.80 nutrient / $258.03 total per cycle / roughly $43 per plant

Two different questions get two different answers here, and it is worth being clear about which one you are actually asking. If the question is which system costs the least to keep running for one tent, AutoPot wins. If the question is which system feeds a plant for the least money, NFT wins by a wide margin, and DWC is actually the most expensive per plant of the three, not because DWC wastes nutrient, but because a single plant reservoir does not get the dilution benefit that comes from sharing a tank across several plants. Electricity barely moves any of these numbers, the gap between the cheapest and most expensive system electrically is under $14 across a full cycle. Nutrient and plant count are what actually separate them.

Pros and Cons of Each System

AutoPot Hydropak

• No electricity used for irrigation, and nothing to fail if the power goes out mid cycle
• Gravity fed, so it keeps running unattended for weeks at a time
• Efficient per plant nutrient use, close to NFT
• Lower plant count per kit than NFT, the starter kit runs 2 plant sites
• Best suited to larger, longer season fruiting crops rather than a fast turnover of small plants
• Reservoir still needs a manual refill every few weeks, it is low maintenance rather than zero maintenance

Oxypot DWC

• Cheapest hardware entry point at $99.95 for a single plant system
• Minimal medium, just clay pebbles, and barely any electricity for the air pump
• Fast growth rate thanks to constant oxygenation at the root zone
• Least nutrient efficient per plant of the three, since the reservoir only ever serves one plant
• Air pump has to run 24/7, if it fails the roots lose oxygen quickly

Gro-Tank NFT

• Most nutrient efficient per plant of the three, since one tank and one reservoir change feeds several plants at once
• No growing medium needed at all beyond the net pots themselves
• Highest total running cost of the three per system, but that is because it is feeding roughly six times the plants of the Oxypot
• Continuous flow system, if the pump stops the roots dry out fast since there is no standing reservoir holding them
• Well suited to fast growing, shallow rooted crops rather than large single plants

What Each System Is Actually Best For

AutoPot suits growers wanting a smaller number of larger plants over a full season, tomatoes, capsicum and similar fruiting crops are what AutoPot's own documentation points to, and the hands off nature of a gravity fed system matches a longer, slower grow well. It also happens to be nutrient efficient per plant, close to NFT.

Oxypot DWC suits a single fast growing plant where you want maximum growth rate in a small footprint and the lowest possible hardware cost to get started. The trade off for that simplicity is the least efficient nutrient use per plant of the three, since one plant is carrying the full cost of its own dedicated reservoir.

Gro-Tank NFT suits growers wanting several smaller plants on the go at once, lettuce, herbs and other quick, shallow rooted crops are the classic NFT use case, and it is the most nutrient efficient option per plant once you are running more than one or two. If you are running a fast crop like lettuce rather than a 16 week fruiting cycle, NFT can turn over 2 to 3 harvests in the time AutoPot or Oxypot complete one, which pushes the per plant cost down further still.

A Note on Electricity Rates by State

All figures above use Victoria's current rate of 25.5c per kWh. If you are in South Australia, expect these numbers to run higher across the board, SA currently sits at 32.6c per kWh, the highest in the country. Our running costs guide has the full state by state breakdown if you want to recalculate for your own rate.

For the full range of systems and nutrients covered in this guide, browse the Hydroponic Systems collection and the Base Nutrients collection. If you are still working out what to feed whichever system you land on, our best hydroponic nutrients guide covers that in full.

Still deciding? Our Grow Tent Kit Builder picks between these systems based on your experience and what you're growing.

Frequently Asked Questions

Which hydroponic system is cheapest to run in Australia?
Depends what you are measuring. AutoPot is cheapest per system, around $172 over a full cycle. NFT is cheapest per plant, since one tank and reservoir feeds several plants rather than one, working out to roughly $43 per plant against Oxypot's $189 for its single plant.

Do NFT systems really use more nutrient than other hydroponic methods?
Not once you account for plant count. A single NFT tank costs more to run than a single plant DWC bucket in raw dollars, but that tank is usually feeding five or six plants at once rather than one. Per plant, NFT is among the most nutrient efficient hydroponic methods, in line with the general principle that a recirculating, shallow film system with no growing media wastes very little.

Does AutoPot really use no electricity?
Yes, for irrigation specifically. The Smart Valve is entirely gravity fed, no pump, no timer, no power draw. The only electricity in an AutoPot setup comes from whatever light and fans you are running alongside it.

Does the growing medium make a big difference to running cost?
Not really. Net pots and clay pebbles are both reused across cycles rather than replaced each time, so the medium cost is closer to a one off purchase than a recurring running cost. It matters far more for upfront cost than for ongoing running cost.

Is electricity or nutrient the bigger running cost for a hydroponic system?
Nutrient, once you get past the light itself. The pump or air pump difference between these three systems only adds up to a few dollars per cycle. The light is the dominant electricity cost regardless of which system it is paired with, and how many plants share a reservoir is what actually separates one system's nutrient cost from another's.