Choose based on how many people will use the system and when you’ll need water most (meals, workouts, breaks, guests). Bigger systems prevent delays during peak use.
- 6L – Best for 1–2 people, fits up to 2 filters
- 9L – Suitable for 2-3 people, fits up to 4 filters
- 12L – Great for families, offices, or entertaining, fits up to 4 filters with faster flow
🟢 Should I size up? Yes—if in doubt, go larger. The price difference is minimal, and a larger model offers more convenience, flexibility, and speed. You won't need to fill your system as often.
🟢 What if my needs change? AQUA Coldstream systems are built to last. Consider future growth (family, usage) so you don’t outgrow your system too soon.
Which filters are used with my AQUA Coldstream system?
The AQUA Coldstream systems use the Coldstream FTO+ filters. These filters have been independantly tested according to NSF standards. Each filter has a lifespan of 1,500 liters.
How much water can my AQUA Coldstream system hold?
The AQUA Coldstream system 6L, 9L, or 12L refers to the capacity of the lower reservoir, which can respectively hold up to 6 liters, 9 liters, or 12 liters of filtered water at a time.
Each Coldstream FTO+ filter takes up about 1 liter of space in the upper reservoir, so the actual volume of water you can pour in will be slightly less. As filtered water moves into the lower chamber, you can refill the upper chamber to continue filtering more.
Important tip: Make sure not to add more water into the upper chamber than what the lower reservoir can currently hold, otherwise the system may overflow between the two chambers.
Does AQUA Coldstream alkalize my water?
No. The Coldstream FTO+ filters included in the AQUA Coldstream system purify water but they do not alkalize it
To alkalize your water and improve its quality, we recommend to pair the system with other water enhancement products, such as the MAYU Mineral Drops or the Vitalizer Plus.
How many filters can my AQUA Coldstream hold?
- The AQUA Coldstream 6L can hold 2 Coldstream FTO+ filters.
- The AQUA Coldstream 9L can hold 4 Coldstream FTO+ filters.
- The AQUA Coldstream 12L can hold 4 Coldstream FTO+ filters.
All AQUA Coldstream system purchases include 2 Coldstream FTO+ filters, regardless of size.
Both the AQUA Coldstream 9L and 12L come with two blocking plugs, so that the unused filter spots can be blocked if they are not used.
Customers can also install additional Coldstream FTO+ filters if they wish to increase the flow rate of filtered water.
What is the total filtration capacity of my AQUA Coldstream system?
Every Coldstream FTO+ filter has a filtration lifespan of 1,500 liters.
To find out the total filtration capacity of your system, you simply need to multiply the number of filters installed by 1,500 liters.
For example:
- 1 filter = 1,500 liters total lifespan of system.
- 2 filters = 3,000 liters total lifespan of system.
- 3 filters = 4,500 liters total lifespan of system.
- 4 filters = 6,000 liters total lifespan of system.
How to know when to replace my filters?
Based on your water consumption, the simplest way to estimate when to replace your Coldstream FTO+ filters is to count how many times you completely fill your system each week.
Here’s how to do it:
- Note how many times per week you fully fill your reservoir.
- Multiply that number by the capacity of your reservoir (in liters).
- This will give you an estimate of your weekly water usage.
- Then divide 3,000 liters (the total capacity of two FTO+ filters) by your weekly usage to find out how many weeks your filters will last.
A good rule of thumb: if you consume an average of 8 liters per day, you will need to replace both FTO+ filters after about once a year.
That said, don’t worry if your estimate isn’t exact — the filters are tested up to 3,000 liters each, which is double the recommended usage. Your FTO+ will still filter your water even after 1,500 liters, but the performance will start to decline.
How to store my Coldstream FTO+ filters?
For storage, the Coldstream FTO+ filters can be fully dried out for several days, then:
- placed in a plastic bag in the refrigerator for short-term storage,
- or in a paper bag (that can breathe) for long-term storage.
Can I filter water from a well?
You can absolutely use the AQUA Coldstream system with your well water. The Coldstream FTO+ filters are designed for deep filtration: bacteria, viruses, pesticides, heavy metals, chemical residues, etc.
Can I filter sea (salt) water through my AQUA Coldstream water filtration system?
No. Coldstream FTO+ filters do not remove minerals from water. Furthermore, the concentration of salt in seawater will ruin the filters.
Can I filter water from my salt-based water softener?
If you use a salt-based water softener to reduce the problems associated with hard water in your home, just as with sea water, AQUA Coldstream systems will not remove salt present in the treated water. If you want to eliminate salt from your drinking water, you must either:
- Use your Coldstream FTO+ water filter with water taken on the water line BEFORE the softener,
- Change your water softener for a salt-less system or
- Use a membrane treatment filtration system after the softener to remove the salt.
Can I use the AQUA Coldstream with my CPAP machine?
No, CPAP machines require demineralized water, and AQUA Coldstream systems does not remove minerals from water.
The 2 chambers of my AQUA Coldstream system are nested into each other, how to open them apart?
If the two chambers of your AQUA Coldstream system you received are stuck together, try having another person help you: one person can hold the bottom chamber while the other gently pulls the top one. Sometimes the plastic rim between the two can fold in on itself, making separation more difficult.