Equally treating double water tanks

[n0ukf]

When treating the water tanks after winter, Dad has a concern about the chemicals (bleach or whatever) getting equally distributed between them. He thinks that if they are poured in very early or late, one tank will be treated more than the other. What is the most reliable way to get equal treatment?

[Morich]

I would feel this is overthinking it a bit too much. Start with the thought that chlorine treatment is an estimate at best. It is designed to get enough PPM to kill the bad guys under normal circumstances. But what is a "normal"? Is it a newish tank setting for two months or a ten year old tank setting for six months? What we need is enough chlorine to react with the things (organics) that it finds and still have some left (3PPM?) but not enough left to kill the good bacteria in our gut.
One practical way to deal with the question is to run the bleach into the first tank and let it be carried into the second tank and assume there is enough to go around. But one can also go further and add double if you choose and just drain and flush it all before drinking from it.
Tap water is normally set to be between 10 and 3 PPM as folks closer to the treatment plant get stronger than those out further. At best it is a treatment written as if it was very precise but is an estimate that can vary quite a lot. It depends on how much other stuff like dirt or algae it finds to react with beside the bad bugs!

[Shedboy]

Agree with Morich. The simple answer is to squirt enough bleach to get 5 ppm into the filler hose before filling the tanks. This will assure that the second tank will be sanitized before the first. The second tank will have a stronger solution than the first but the first tank will have a longer exposure time before use. If you can smell bleach in the water exiting the sink faucet, it's too much bleach.


Keep in mind:
Bleach sanitizes the water from most organics, not metals or some pathogens
the effectiveness of bleach depends on time of contact with the water as well as the strength
bleach deteriorates with time, it becomes less potent
bleach can (rarely) contaminate the water, particularly if alum is present in the water supply


Most common contamination problems that bleach treats originate with mammals; e-coli, giardia, samonella and some forms of algae.


Keeping the black water away from the drinking water prevents many contamination problems. Care at RV dump sites and sanitary dumping practices as well as care in handling and storing hoses and equipment is important.


When boon-docking, a 3-5 micron filter in addition to the bleach is useful when filling from lakes or streams. Although the bleach will sanitize the organics with time, larger organisms such as algea and "beaver fever" will immediately be trapped in the filer media