Water Pumps and Water Tanks.

[Formaleins]

Here is a question for you, would anyone hazard a guess if these two methods of getting water out of my tanks will make any difference or not - I am struggling to see anything negative but maybe someone here has done it and got the T shirt.

 

Currently the 2.5 metre tall  tank(about 2000 Litre)  is filled via the government mains with a ballcock type shut off. This is then delivered across about 20-25M run from the bottom of the tank into a rather small (same as the supply 3/4" pipe) To our home pump which supplies the house - ( The home pump is a 1.25" Hitachi that can lift from about 3M and pump at 325 Ltr / Min.)

 

I need to make some changes as the initial tank has started leaking so the proposed changes would be to feed the home pump from a pipe that goes into the tank from the top at about 2.5M and sucks the water out using 1.5" pipe, across the 20 metre run and then feed it into about 3 Metres of reduced diameter (1.25" pipe ) to the home pump.

 

Anyone see any pitfalls? To me there will be a benefit of no longer starving the 1.25" feed to the home pump by cutting off the 3/4" feed and replacing it with a 1.5-1.25" feed. Also, I may be wrong, but using the syphon type suction out of the tank rather than the bottom of the tank pressure, it migh even be cleaner.

 

Please refer to my terrible diagram if you need a pictorial. As always, your help is greatly appreciated!

[CharlieH]

Wrong forum - MOVED to DIY

[Momofarang]

Currently I have option B for watering my garden. But I will move to A because with B I tend to clog up my pump with the iron oxyde that precipitates in the tank. A will allow me to pump some 50 cm above the deposit at he the bottom of tank. Bear in mind that with A priming the pump can be a bit tricky;  I'll put I pipe from the main water supply with a tap on top of the tank for priming.

But to answer your question if your town water is clean you should be perfectly fine with A, just insert a strainer before the pump (or the check valve) to cater for the inevitable dead gecko.

Edited January 10, 2020 by Momofarang

[Formaleins]

13 minutes ago, Momofarang said:

Currently I have option B for watering my garden. But I will move to A because with B I tend to clog up my pump with the iron oxyde that precipitates in the tank. A will allow me to pump some 50 cm above the deposit at he the bottom of tank. Bear in mind that with A priming the pump can be a bit tricky;  I'll put I pipe from the main water supply with a tap on top of tank for priming.

Ha ha! The iron oxide! the nemesis of all ground water installations. I spent 10K Baht about 15 years ago on a system to get rid of the iron oxide, manganese carbon and a load of other garbage, it did not work. We eventually plumbed two of these 2000 litre concrete tanks together and filled each one with small stones / gravel to about 50cm then layered on another 50 cm of sand, this completely got rid of the iron, but it required regular flushing which was a big PITA - every two or three weeks if I remember, up ladders fighting red ants anf Jakep /Takarp.

 

Problem I have at the minute is the main tank appears to have become porous and leaks through the concrete rings. I have disconnected it and will let it dry for a week then try to re render it from the inside with a scree and a waterproofing agent from Weber. see if it works or not. but no way am I going back to the sand filter iron oxide ground water because my wife insisted on us connecting to the government water, (and I humbly obeyed) providing she paid the monthly bill, which she is now stuck with, which for me is a win win situation.

 

Understand what you mean about priming the pump as well, I have another 3 groundwater pumps for the land and yes they can be another pain to keep primed.

Edited January 10, 2020 by Formaleins

[sometimewoodworker]

1 hour ago, Formaleins said:

I have disconnected it and will let it dry for a week then try to re render it from the inside with a scree and a waterproofing agent from Weber. see if it works or not.

Rather than the Weber product you could use Flintkote or DrFixit both are bitumen products. 

[impulse]

On option B, it shouldn't be that difficult to insert a curved section of pipe into the tank and take suction at the same level as you can achieve with option A.  Replace the 3/4" pump inlet pipe with a 20 meter shot of 1.5" and you have the benefits of A without the priming issues. 

 

The biggest downfall I see is that you'd have to drain the tank to address any dead tokays in your strainer.  With option A, you can pull the whole mess without draining the tank.  But then you'd always wonder...  Do I have a plugged screen or just lost my prime?