Water Tank

Water is all you can think about if you are out of water.  I never fully understood until we ran out of water.  For 6 years I had to haul water to supplement a well.  We finally drilled a new one and have a good source of water but I kept the tanks and pumps for emergencies and as a handy source of water for sites without a supply.   

Tanks

During my working career as a Agricultural Researcher, I used a variety of tanks ranging in size from 20 to 1,000 gallons.  I found the 20 to 60 gallons tanks were handy because they were easy to get in and out of a pickup truck.   Larger tanks required extra workers to move or their own vehicle i.e.. water truck or trailer but provided more water.   The other consideration is the weight of water.  For simple calculation a gallon of water is 8 lbs. so a 100 gallon tank full of water is 870 lbs. if you include the weight of the tank, water, 12 v pump and battery.   It adds up fast.  

Pumps

Keep it simple.  For years, I used gravity to get the water out of the tank.  Gravity worked great until I need to fill sprayers higher than my water tank.  The easy solution was to use 12 volt RV pumps, but used gas powered pumps when larger volumes of water were needed.  The RV pumps flow ratings range from 1 to 7 gallons per minute.  The battery size should be paired to the pump size and recommend 2X amps battery for the pump amp rating.  

Thoughts and Hacks

1. Do not let the pump freeze.  Replacement parts are available but expensive.  Consider just upgrading the pump instead of repair.

2. Pair pump output with gpm water needs.   This reduces pump turning off and on when low flow rates are needed.  

3. Consider a small RV pressure tank or bypass tubing if low gpm is being used.  

4. Make pumps easy to detach from the tank for winter storage.  I use quick couplers for garden hoses.

5. Include an shut off valve between tank and pump so tank does not need to be empty to detach pump.  

6. Remove all the water when tank is not being used because algae loves to grow in them.  

7. Consider treating the water in the tank with chlorine if for drinking or just general algae reduction.  

8. Pump manufactures often provide a filter between tank and pump.

9. Use an inline drip irrigation filter to remove sediments if water will be used for spraying or drip irrigation.  Remember to clean it often.