Description
The GrowMax Pro RO 3000 is the largest reverse osmosis unit GrowMax build, producing up to 3,000 litres a day at 125 litres an hour. Two 500 GPD membranes running in parallel, so you are not stood waiting on a butt to fill.
Built for rooms where tap water is the limiting factor. It strips out the salts, chlorine and sediment sitting in the background of every feed you mix, so your nutrients do the work instead of fighting whatever came out of the mains.
What it does to your water
- Removes up to 95% of salts and heavy metals
- Removes up to 99% of chlorine
- Reduces sediment to 5 microns
- Drops your starting EC, so you control the whole feed rather than topping up what is already in there
- Helps stabilise pH and cuts the swing you get on hard water
- Avoids the lockout caused by background calcium and magnesium
- Protects reflectors, carbon filters and bulbs from mineral deposits
Specification
| Output | Up to 3,000 litres per day |
| Flow rate | 125 litres per hour |
| Membranes | 2 x 500 GPD |
| Minimum inlet pressure | 4 bar / 57 PSI |
| Maximum inlet pressure | 6 bar / 85 PSI |
| Water supply | Cold only, max 25°C |
| Cartridge life | Around 40,000 litres filtered |
| Connection | Tap or fixed pipework |
| Setup | Ready to run out of the box |
Check your water pressure first
The 3000 needs 4 bar / 57 PSI minimum and must not exceed 6 bar / 85 PSI. That is a higher requirement than the smaller GrowMax units, so check yours before ordering. Above 6 bar, fit a pressure regulator. Below 4 bar, see the booster pump question below. Cold supply only, maximum 25°C, and protect the unit from frost.
On hard water? Check your TDS too
GrowMax rate their RO systems for up to 1000 TDS at 60 PSI, rising to a maximum of 1500 TDS once pressure is pushed above 60 PSI. The 3000 already wants 4 bar (57 PSI) as a minimum and will run up to 6 bar, so a supply at the top of that window is doing what a booster does on the smaller units. Neither GrowMax booster kit fits this unit, so if your mains will not get you there, see the pressure question below. Whatever the pressure, the higher your incoming TDS the lower the output. Most UK tap water sits well inside 1000, but boreholes and the harder areas do not.
When to change the filters
| RO Membrane (500 GPD) | 6 months to 2 years, depending on use and input EC |
| Green Coconut Carbon Block Filter | Every 6 months |
Frequently asked questions
My pressure is under 4 bar. What do I need?
Not a GrowMax booster kit. Those are made for the smaller units: the standard kit is specified for the Power Grow 500 and Maxquarium 000, and the High Flow kit for the Mega Grow 1000. They shift 0.26 and 0.6 GPM and boost to around 60 PSI, which is neither the flow nor the pressure a 3000 needs.
What you want is a proper mains booster set. The DAB Esybox Mini 3 reaches 5.5 bar at up to 70 litres a minute, which sits inside the 3000's 4 to 6 bar window with room to spare. Our Clarke CBP900 and DAB Esybox Pop both stop at 3.2 bar, so neither will get you there for this unit.
Note that DAB units are fed from a break tank or storage cistern rather than straight off the mains, which is what UK water regulations require. Not sure what you have? Send us a photo of your supply and we will tell you.
My water is over 1000 TDS. Will it still work?
Yes, up to a point. GrowMax quote 1000 TDS at 60 PSI and a ceiling of 1500 TDS with pressure above 60 PSI. Because the 3000 runs on a 4 to 6 bar supply, a mains pressure in the upper half of that range is already giving you the headroom a booster gives the smaller units. If yours is at the bottom of the window and your TDS is high, the DAB Esybox Mini 3 is the route. Expect lower output the higher your incoming TDS, whatever you do about pressure.
How much waste water does it make?
Every RO unit produces a waste stream, and the ratio depends on your input pressure and water quality. Higher pressure means less waste. Run the drain line to a gully, or catch it for anything that does not need pure water.
Will it get me to 0 PPM?
Close, but not quite. RO removes up to 95% of dissolved solids, so on hard UK water you will land in the low tens of PPM. For true 0 PPM, add a 10" De-Ionization Filter after the RO stage.
Can I leave it running unattended?
Fit a Float Kit and it shuts off when the tank is full. Without one you need to be there to turn it off, and 125 litres an hour fills a butt quickly.
Which spares fit this unit?
The 3000 takes its own 500 GPD membrane and a Green Coconut carbon block, not the 10" filter packs the smaller units use. Full chart below.
GrowMax Compatibility Guide
Not sure which spare part fits your unit? Full compatibility chart below, covering every GrowMax RO system and filter pack we stock.
| Part | Power Grow 500 | Mega Grow 1000 | Maxquarium 000 | Water Max 700 | Water 3000 (this unit) | Garden Grow |
|---|---|---|---|---|---|---|
| 10" Filter Pack (carbon + sediment) | ✓ | ✓ | ✓ | ? | — | — |
| Mega Grow 1000 Filter Pack (2x carbon) | — | ✓ | — | — | — | — |
| RO Membrane 150 GPD | ✓ | ✓ | ✓ | ? | — | — |
| 3000 Membrane (500 GPD) | — | — | — | — | ✓ | — |
| Green Coconut Carbon Block Filter | — | — | — | — | ✓ | — |
| 10" De-Ionization Filter | ✓ | ✓ | ✓ | ✓ | ✓ | — |
| 10" De-Ionization Filter Kit | ✓ | ✓ | ✓ | ✓ | ✓ | — |
| Booster Pump Kit | ✓ | — | ✓ | — | — | — |
| High Flow Booster Pump Kit | — | ✓ | — | — | — | — |
| RO Float Kit | ✓ | ✓ | ✓ | ? | ✓ | — |
| 1/4" Black Drain Tubing | ✓ | ✓ | ✓ | ? | ? | — |
| 3/8" Blue Feed Tubing | ✓ | ✓ | ✓ | ? | ✓ | ✓ |
✓ compatible · — not compatible / not applicable · ? not confirmed by GrowMax, check before ordering
