Safe drinking water on board: clean water for your motorhome, boat, and caravan

Safe on-board drinking water depends on three things: a clean water tank, good hygiene when refilling, and continuous water treatment to keep quality stable when water is stagnant. Doing this reduces the risk of off-flavors and odors, and you won’t have to start over every time you refill.

Tips

Clean your water tank before the season starts and after prolonged periods of stagnation
Always refill from a tap using drinking water you trust
Flush the hose for a short time before refilling
Store the hose in a dry, clean place so the hose end does not get dirty
Add treatment tablets when refilling your water tank
Dose based on the amount of new water added, rather than the full tank volume, when the tank is not completely empty

Step-by-Step: Get Clean Water in Your Water Tank and Pipes

Clean Your Water Tank and Hoses
Deposits can build up in the tank and hoses when water is stagnant. Clean the entire system regularly as a result. Fill the tank and system according to the product’s instructions. Let the solution work for at least 12 hours. Then drain the water via the bottom plug or tap.
Refill Properly
Use drinking water of approved quality. Flush the hose before connecting it for refilling. Avoid letting the hose end touch the ground. Keep connections clean and allow the hose to dry after use.
Add Water Treatment When Refilling
Add water treatment directly to the water tank when filling or topping up with new water. Let the treatment work for at least three hours before use.
Dose Based on Refill Amount
If the tank already contains water, only dose for the amount of new water you are adding. This is especially important if you frequently refill small amounts at a time.
In-Season Maintenance
Hot weather and stagnant water cause water quality to degrade faster. Pay extra attention to hygiene during refilling and dosing if your vehicle is left stationary for several days.

Dosing Chart: Drinking Water Treatment

The chart below is tailored to the package sizes for Biocool Purify my drinking water and the dosing guidelines listed on the product.

Package Size	Covers Volume	Dosing Instructions	Recommended For
10 Tablets	50 Liters of Water	1 tablet per 5 liters of water. Let the treatment work for at least three hours before use.	Water jugs or smaller tanks up to 50 liters.
250 Tablets	1250 Liters of Water	1 tablet per 5 liters of water. Let the treatment work for at least three hours before use.	Tanks up to 100 liters with regular refills
450 ml Powder	3000 Liters of Water	1 scoop (15 ml) per 100 liters of water. Let the treatment work for at least three hours before use.	Tanks 100 liters and larger, and for those who prefer dosing with a scoop.

Why Water Quality Degrades in Tanks

Stagnant water loses quality over time. Off-flavors and odors can develop when water sits for long periods, especially in hot conditions.
Deposits Affect New Water If the tank and hoses are not clean, deposits can contribute to poor water quality even after refilling.
Refilling Hygiene Is Critical The hose, connections, and storage determine how much contaminants you introduce into the system.
Water treatment is regular maintenance, not a one-time fix. Dose when refilling and let the treatment work for the recommended duration.
Consistent Routines Save Time When your tank is clean and you dose consistently, you won’t have to troubleshoot off-flavors and odors during your trip.

Frequently Asked Questions

How Often Should I Clean My Water Tank?
Before the season starts and after prolonged periods of stagnation. If you use the system frequently, it’s a good idea to implement a regular cleaning routine throughout the year.

Why Isn’t Refilling With New Water Always Enough?
Deposits can remain on the tank’s surfaces and in the hoses. When you refill, these can affect the quality of the new water.

When Can I Drink the Water After Dosing Water Treatment?
Wait at least three hours before using the water.

What If I Refill Small Amounts Frequently?
Only dose for the amount of water you are adding, not the full tank volume if the tank already contains water.

How Long Will the Water Maintain Good Quality?
This depends on temperature, refilling hygiene, and how clean your tank is. Follow the dosing instructions and dose when refilling for consistent water quality.