I need help. I want to install a tank for water storage. Filling up a very larg tank is ok, but rotating the water is the problem. So I was thinking
Why can,t I install a water tank to existing plumping. Install a water tank in the basement, I would connect the water pipe into the tank. This would just be a catchment of water. I would be rotating the water everyday just because we are using the water.
If the city water was cut off I would have the catchment of water. I would not have to worry about rotation of the water. This is my thinking , can't be done?
I am not expert but I would think the tank needs a pressure rating on it.
I believe you could do it, hooking a tank in with the existing provided you hook to the existing so that you will able to isolate your tank.
Without your municipal pressure you will need to be able to pressurize your water tank to supply your home.
Average pressure rating for city water is 40-70 psi. So your tank should also be at this pressure rating. One other thing I would add is a back flow stop. If there is a power failure, the city water pressure could go into the minus, sucking out your water. People that live in a no freeze zone, use water towers for emergency pressure.
"We 'Prep.' to live after a downfall, Not just to survive."
Absolutely correct Ranger. But going a little further EVERYONE should install a back flow valve. It prevents all water in your system, including the hot water tank, from draining backwards into the municipal system if the pressure drops. During "normal" it can save your hot water tank from burning out if there is an absence of pressure in the municipal system. During a SHTF situation if the water system fails you will still have the 40 gals or so in your hot water tank to fall back on.
Adding a tank in your basement down the line from a back flow valve but still on your main line before the hot water tank and other house line would provide you with a large extra supply of clean drinkable water in the event of a catastrophic event. It will not pressurize your system though, you would have to have the means to drain the tank to gain access to the water.
By the way it is a great idea giving you 50 gals or so (depending on the size of your tank) of easily accessed drinkable water! Try to collect 50gals of rainwater and the purifying it. It can be done but this idea is brilliant!
Thank you so much for the help. I now have An idea what I am looking for.
The other Idea if you want a non pressured system, is have a side line going to your tank, and use a water level valve on the out put. If you want to be sure that the water is circulated, add a water pump to your out flow valve, and hook it up to the water hose, for your garden. "There is always, a way. Just that, someways are a little harder than others." JT 
"We 'Prep.' to live after a downfall, Not just to survive."
you could also twin a second hotwater tank to your existing one and double your hot water supply.
I realize that this is an old thread, but I just have to put in my 2 cents.
Storing unheated water in a tank that is directly connected to your plumbing system is not a good idea. By plumbing code, a water heater must maintain a temperature of not less than 140°f. This is to kill any bacteria, such as Legionella. Storing water at any temperature less than this could cause bacteria to flourish in this environment. Even if you plumb the tank in series, the unheated water will not be moving fast enough to prevent a buildup of bacteria.
I, too, am looking for a method to store water in the event of a loss of city water. Our city has water towers, so there would be water pressure for a bit after a power outage. I am thinking about a collapsible water storage container that I could fill up when I feel threatened by a water shortage.
Also, I think that backflow preventers are a good idea. They are also code in a lot of municipalities, although it is not always enforced. When a backflow preventer is installed, you must also install an expansion tank. Normally, when your cold water is heated by your hot water tank, the water expands in volume and the extra volume gets pushed back into the city water system. With a backflow preventer, the extra volume cannot get pushed back, so you need an expansion tank to safely absorb the extra volume.
For a great way to store water while there is still pressure after an emergency, I would recommend looking into an aquapod, or other similar system.
It is basically a collapsible water storage system that sits in your bathtub, and uses the tub to prevent the pressure from the water volume to stop it from bursting at the seams. The version I purchased comes with a hand pump on top.
In regards to an inline water storage system, I was thinking of something similar in upcoming home renos.
If water storage in 55gal plastic drums is deemed suitable water storage, why would a constant turnover in water supply be a breeding ground for bacteria, where the plastic drum would not?
If this is, in fact a valid concern, would a UV filter either before or after the storage tank suffice to remove bacteria?
I am not sure that water stored in 50 gallon drums would be considered "potable" water. All the water in your pressurized domestic water system must be potable. Unless you have a pressure vessel that is specifically designed to store potable cold water while protecting against bacterial growth, I would not do it. If you have a 3/4" line going in and a 3/4" line coming out, nothing guarantees that all the water will be changed regularly.
I liked the idea of keeping a 50 gallon drum filled and pumping the water to water plants, flush toilets, wash the car, or whatever.
Just trying to contribute, as this is my line of work.
I would think that if you have a supply of water... potable or not... you could use it once you put it through a purifyer/filter and added a little chlorine. Thoughts?
JAB
Exactly my thought as well. Keep a barrel of water and use it for other things normally, and it is there to filter and drink when you need it.
Storing unheated water in a tank that is directly connected to your plumbing system is not a good idea.
If an approved water tank is plumbed in "in series" with your main waterline before the line is split to the various distribution lines in your house all the water coming from the municipal water supply will be running through it. This water will be chlorinated to a level that will not allow the growth of bacteria.
Look in the tank on the back of your toilet. Mine has brown scum, even though there are many water changes every day, and I have city water with chlorine. Anyone on a private water supply would not likely have chlorine. I guess the bottom line is that it is not illegal according to plumbing code, and you are free to do it, but I would not.