Growmax Reverse Osmosis Filters

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  • Eliminates 95%, of salts and heavy metals.
  • Helps stabilize pH.
  • Great for organic growers!
  • Protects beneficial micro-organisms in your soil.
  • Get 100% effectiveness from your nutrients and fertilizers.
  • Faster growing plants and gardens.
  • Healthier fruits and vegetables.
  • Can be mounted on a wall
  • Requires no input other than water pressure
  • Comes complete with all fixtures and fittings

How Do Reverse Osmosis Water Filters Help Hydroponic Gardeners?

Reverse Osmosis (RO) water systems optimise hydroponic gardens. RO water filters eliminate up to 95% of all of salts and heavy metals as well as immediately eliminating 99% of chlorine and sediments down to 5 microns!

RO water filters utilise a semi-permeable membrane to remove larger particles such as bacteria, molecules and ions from the source water (usually tap water). RO membranes retain impurities on one side of the membrane, while the pure water freely passes to the other side through the pores in the membrane.

Eliminates or Reduces: Salts, heavy metals, chloramines, nitrates, nitrites, chlorine. Sediment; dirt, rust, oxidation. Herbicides and pesticides, volatile organic contaminants. Chemical contaminants, benzenes, toluene, oils, THM's, detergents, PCB's)

The Power Grow unit produces 500 L/D (20 L/H) whilst the Mega Grow unit can produce up to 1000 L/D (40 L/H).

Reverse Osmosis water filters allow you to create a blank canvas, producing near zero ppm pure water, devoid of most dissolved salts, straight from the tap. Mains tap water can contain chlorine, chloramines, copper, nitrates, nitrites, phosphates and silicates. When used untreated, straight tap water can be harmful to the beneficial fungi, microbes and bacteria in soil and hydroponic applications. Using RO water as the base for your nutrient solution, leads to faster growing, healthier plants.

Should I Use An RO FIlter?

To find out if you could benefit by using an RO filter for your watering requirements, simply measure your tap water supply with a TDS meter. If your tap water is greater than 10 ppm, you will likely see improved results from RO water. The higher the reading, the more benefit you'll gain. Setting your reservoir water profile to near zero ppm gives you more confidence your feeding the correct nutrient levels when you mix your nutrients. EC/CF measurements for nutrient mixes are a lot more accurate with near-zero ppm base water. Improved accuracy means you can keep better records and repeat nutrient mixes time after time for future grows.

How Often Should You Change RO Filters?

We recommend you change your filters once every six months to maintain the reverse osmosis filters efficiency.

How to Use

Garden tip:

  • The RO filter unit operates with mains pressure between minimum 40 psi to a maximum of 80 psi. Water pressures over 80 psi require you to fit a pressure regulator to reduce pressure to an acceptable level.

  • 1. Simply install the inlet pipe onto a garden tap or faucet and connect this to the unit with a length of 3/8" tubing.

    2. You can now connect the unit to your garden hose using the outlet and another piece of 3/8" tube.

    3. Alternatively, you can run the 3/8" tube directly to your garden or a reservoir for storage for later use.

    4. Discard the first 15 minutes worth of water when the system is new or if filters have been replaced, the PPM and pH of the water will stabilise over the first 24 hour period.

    Customer Questions
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    Next Day Delivery

    Our UK Mainland delivery service is provided by Parcelforce Worldwide.

    NOTE: For anyone outside of the UK (i.e. Republic of Ireland and the EU) you are free to arrange your own courier service. To order from us using your own courier, complete your purchase from our website, and select "Collect from our Warehouse — Chigwell". This is where you can arrange your own courier to collect your item(s) from. Address details are available on the Contacts page.

    Standard UK mainland orders over £50.00 are eligible for a free standard next working day delivery service (Mon – Fri)*.

    • *Free delivery includes orders up to, and not exceeding, 30kg, that fit in a single, standard shipping box.
    • *Free delivery may exclude orders containing one or more large volume items. Examples of large volume items are, but are not limited to, bags of media (clay balls, perlite, soil etc.).
    • *Free delivery excludes Garden Power Tools.
    • *Large items are sent via a standard 48L (48 hour large) service. Large items take from 2 working days to arrive.

    Where possible, orders received by 2:30pm Mon – Fri are dispatched the same day. (*Excluding Garden Power Tools).

    Where possible, Garden Power Tool orders are dispatched the same day when received by 11:00am Mon – Fri. Orders after 11:00am are usually dispatched the next working day

    UK mainland orders after 2:30pm Mon - Fri are subject to next working day dispatch:

    • For example, orders after 2:30pm on a Friday are dispatched on the next working day, usually a Monday.

    UK Mainland Pallet deliveries are charged separately per pallet. They are usually delivered in 2-3 working days. Please contact us for the latest cost price.

      Our shipping providers terms and conditions limit our ability to send some products internationally. See our list of restricted items.

      All prices shown below are per parcel with a maximum weight of 30 kg per parcel. Items over 30 kg are split into multiple boxes and charged per box.

      Future Garden are not liable for any additional fees that may be incurred. Any unexpected costs must be paid by you (the customer).

      Delivery services provided online are estimates. There may be unforeseen delays with your order, especially around our busiest time of year. Very busy periods can see very high volumes of parcels being collected, processed and delivered. If you have a special delivery requirement, please contact us via email - before placing your order.

      UK Mainland

      Standard Next Working Day (Orders over £50 <30 kg) FREE
      Standard Next Working Day (Orders under £50 max. 30 kg per parcel)* £6.95
      Standard 2-3 Working Day (Orders under £50 max. 30 kg per parcel)* £4.95
      Pallet Delivery £70.00

      Isle of Wight

      Next Day Service £8.95

      Northern Ireland

      Two Day Service £18.95

      Isle of Man & Scilly Isles

      Two Day Service £20.95

      Scottish Highlands & Islands

      Two Day Service £16.95


      Sorry, no online quotes are available for orders outside of Europe. If you would like to place an order for delivery outside of Europe, email us directly and we can prepare a bespoke quote for you based on the weight, dimensions and destination country for the most accurate cost and quickest delivery times to you.

    As per the Consumer Contract Regulations June 2014, you can return goods and receive a full refund under the following conditions:

    • You have had the goods delivered within seven working days of delivery from Future Garden Ltd, this starts from the day after the goods have been signed for.
    • The items are unopened and in the original condition as when they were delivered to you.


    • The items have developed a fault during standard use.
    • The items are within the manufacturer's warranty period.

    Simple checks

    • Please ensure that any parcels delivered are intact and free from damage and unopened, if they appear to show any damage please make a note when signing for the goods, alternatively you can refuse delivery of these items, however only full refusal if multiple parcels will be accepted, in the unlikely event this occurs please contact us asap on 020 8502 7722 or by email
    • Please check all items once unboxed to ensure that they are not damaged and are fully functioning, if this is not the case please ensure you notify us as soon as you can, or within the given returns policy time frame, on 020 8502 7722 or by email  we will then arrange suitable collection and replacements where necessary.
    • If any items appear not to be functioning as expected, do not attempt to fix or tamper with any products, this could affect your statutory rights, please notify us on 020 8502 7722 or by email and we will arrange a suitable replacement.
    • If you notice any irregularities with your order, please notify us as soon as possible or within 7 working days, on 020 8502 7722 or by email will endeavour to correct and refund where possible. 
    • You can return any unwanted items, you can return the item(s) to us unopened and intact in a re-sellable condition within 14 working days after the day of receiving the goods, we are unable to accept any goods back that have been opened or the seal(s) have been broken or have been damaged, unless reported as damaged in transit, you can contact us on 020 8502 7722 or by email