How to use Aquafighter®

Instructions for use

Aquafighter® removes and captures emulsified water from fuel as well as free water from the bottom of the fuel tank.
  • Long-term & short-term savings on maintenance and capital equipment
  • Demulsifies diesel & biodiesel blends by maintaining water level within fuel specification in the tank at all times
  • Protects fuel tank from microbial growth, corrosion and other related damages due to water accumulation
  • Non-toxic, safe to handle and safe for the environment
  • Stops the domino-effect of water damage from the tank through the fuel system to the engine
  • Manages fuel-quality and fuel tank condition better than other solutions combined

Installation Instructions:

Firstly, identify if possible the current state of the fuel and storage tank:

If you cannot visually see the fuel and inside the fuel tank there are options for you:

  • Take a sample by draining from the bottom of the tank
  • Test that sample for microbial contamination using FUELSTAT
  • Use the Aquafighter Dipstick Indicator to check for water content in the tank through the tank dipstick tube

Tank is clean and Fuel is in good condition with low water content:

  • Install Aquafighter and maintain water-free conditions
  • Check periodically and replace Aquafighter when full or almost full and your tank will not suffer the fate of the next 3 examples

Fuel has significant water content (high ppm):

  • Aquafighter can be installed to remove bound/emulsified water
  • Aquafighter should be checked after two days from these conditions to see if Aquafighter is full or almost full
  • If it is full or almost full, replace and maintain water-free conditions

Fuel and Tank have significant water content (high ppm) and significant dirt and microbial content:

  • Tank should be emptied and cleaned first to prevent this dirt and microbial growth from clogging filters and getting into machines
  • Clean fuel replaced
  • Aquafighter can be installed to remove bound/emulsified water
  • Check for levels of microbial contamination in the fuel using FUELSTAT test kit
  • It only makes sense to care for your tank so that your fuel will treat your machines well

Fuel has significant water content (high ppm):

  • Whether you use Aquafighter or not, if your tank looks like this, you should not put this fuel in anything of value
  • Empty and clean this tank thoroughly and visually inspected if possible before re-use
  • Clean fuel replaced
  • Install Aquafighter and begin a new era of clean tank and clear & bright fuel
  • Check for levels of microbial contamination in the fuel using FUELSTAT test kit

Next, select the correct size Aquafighter for your fuel storage tank:

Check the opening size of the tank first, and then the capacity of the tank. Choose an Aquafighter® that suits your maintenance schedules from the table below:

Choose your

Aquafighter logo

Install your Aquafighter®:


  • Carefully remove Aquafighter from the airtight bag
  • Lower Aquafighter into the tank so that the Aquafighter is resting on the bottom at the lowest part of the tank, not suspended in the tank – see illustrations
  • IMPORTANT – take care of the bag as this will be used to contain and/or dispose of the used Aquafighter (see below)
  • Ensure that sufficient length of cord is left outside the tank so that it can be attached, e.g. by making a loop around the filler pipe, or other suitable secure attachment

Removal during operation:

  • If installed in a moving vehicle, before starting the engine, machine, vehicle or boat, the Aquafighter filter MUST be removed from the tank
  • Inspected water content (see detailed description below) and place back in the airtight bag
  • Allow the Aquafighter to drip off excess diesel before placing it in the bag

Replacement after operation:

  • After completing the operation of the boat, vehicle or machine, e.g. at the end of the working day, Aquafighter may again be removed from the airtight bag and lowered back into the diesel tank while securing the cord as described above
  • Aquafighter will then continue absorbing any water that may have entered the tank during the day or trip


  • Pull up the Aquafighter from the bottom of the tank to visually inspect. The Aquafighter must be inspected regularly, e.g. monthly, for water content / water absorption
    • If less than 50% of the Aquafighter has turned red, it can be returned to the tank
    • If more than 50% of the Aquafighter has turned red, replacement is recommended (see “Replacement” below)
  • You can also check to see if your Aquafighter® is full by monitoring water levels in the tank, either:
    • Insert an Aquafighter Dipstick Indicator through the dipstick pipe to detect the presence of bound water. This is the easiest and most accurate method and will let you know if your main Aquafighter is full
    • Monitor the water separator (if installed) for the first traces of water


  • Under normal circumstances and with the correct size Aquafighter for your tank, your Aquafighter will keep your tank completely water-free for at least 1 year. However, there are events such as bad fuel, high humidity and leaks that could affect this. In cases where you have excessive amounts of water in your tank Aquafighter will clear the stated amount of water, saving expensive damage, downtime, cleaning and repairs
  • When more than 50% of the Aquafighter filter has turned red, replacement is recommended
  • Used Aquafighter must be safely placed in the bag it was delivered in, or similar, and disposed of in “special waste”, at your local auto parts store, or in any place oil filters and other similar products are disposed. The used Aquafighter filter will consist mostly of water, but small amounts of diesel can remain, and it should therefore be treated in the same way as other waste fuels, lubricating, or hydraulic oil, fuel and paint residues.


  • When handling the Aquafighter with a risk of diesel exposure, gloves and other adequate protective equipment should be used to avoid contact with skin or eyes. In case of diesel spills and/or diesel getting in contact with the skin or eyes, the procedures described in the diesel safety data sheet (SDS) must be followed
  • When using an Aquafighter for the first time, there may already be a volume free and/or dissolved water in the diesel tank that will be quickly absorbed. Consequently the Aquafighter will reach its maximum capacity and 50% red colour far sooner than normal during this first installation. It is therefore recommended to inspect the Aquafighter on first time installation after maximum of one week. If the Aquafighter needs to be replaced after a week, add a new Aquafighter into the tank and perform a new inspection within a week. Eventually it will take longer and longer between each required replacement with a new Aquafighter. This simply means that the diesel in your tank has reached a level where water is no longer at harmful levels and the conditions for microbes to grow has been removed.
  • In some applications components in a diesel tank can be damaged by use of the Aquafighter whilst the tank is in motion during operation. (ONLY USE WHEN TANK IS STATIONARY)