Water Pump From Filler Tank

[UKJASE]

hey guys, we have just built a house in an area that is yet to get government water

we are intending to get our water tanked in by truck

at the minute we have a 1000 litre tank connected to the house, with a decent mitsubishi pump maintaining the pressure in the water system

we have another 2000 litre tank, situated next to the smaller tank. we want to use this tank as a feeder tank to the smaller tank, so everytime water is taken from the small tank, the big tank pumps some water into the small tank, and maintains that the small tank is always full

then, when we see that the 2000 litre tank is empty, we call the truck, and he comes round and refills the big tank

so my question is, what pump / system is suited to send the water from big tank to small tank?

it will need to work so that everytime the level in small tank drops, it pumps water in until it is full again. the pump will also need to know if the 2000 litre tank has ran dry, so that it doesnt burn out

[lopburi3]

Why not just connect the two tanks together - no extra pump needed and you can still refull when down 2/3rds (same same)? We have two 1,250 liter tanks that way for several decades here in Bangkok with government water (water into tank 1 and out tank 2) - one float valve is all that is needed once public water available - and easy enough to pump water from truck into both tanks if flow between too slow to even up fast enough.

If you need a reminder to fill put a clear stand pipe plastic float on the top of connecting pipe so you have a visual water level as used.

[UKJASE]

Why not just connect the two tanks together - no extra pump needed and you can still refull when down 2/3rds (same same)? We have two 1,250 liter tanks that way for several decades here in Bangkok with government water (water into tank 1 and out tank 2) - one float valve is all that is needed once public water available - and easy enough to pump water from truck into both tanks if flow between too slow to even up fast enough.

If you need a reminder to fill put a clear stand pipe plastic float on the top of connecting pipe so you have a visual water level as used.

thanks Lopburi3, as reliable as gravity can be, i think where we have the tanks positioned is not suitable for that, as they are in the front garden, and if we raised one up, it would be a bit of an eyesore. i suppose we could bury the smaller tank, but that could lead to maintenance problems in the future

[lopburi3]

You don't have to raise anything - you connect near the bottom of each - water will rise to same level in each tank.

[UKJASE]

You don't have to raise anything - you connect near the bottom of each - water will rise to same level in each tank.

yea, but the delivery truck comes round with a 2000 litre tank, so they could perfectly fill the tank each time

.............. now you mention it though, i guess if we got down to the last third on the tanks, and called the top up guy, he could put all 2000 litres into the big tank, and a lot of it would transfer to the smaller tank, so we could receive our full truck load

i think i was over analysing this one lopburi!! cheers buddy, i think that is what we will do

[Crossy]

A gravity system will work well, so long as both tanks are the same height, if not the lower tank will fill to the level of the upper tank (and overflow).

To do what was in the OP a cheap pressure controlled pump (the smallest available) feeding a ball valve on the 1000L tank will keep it topped up.

A readily available float switch in the big tank, wired to cut the pump power when the tank is nearly empty, will prevent dry running. The switch could also be wired to a "Tank Empty" light so you don't need to muck about dipping the big tank to see when to call the water truck.