Of course, you can install a valve to control the flow of water from your water tank. Just install it on the pipe leading from the tank to your house. When I was building my house, valves like this were one thing I always had to make sure the builders installed. I wanted them everywhere, in every room with water, and even separately for things like, in a bathroom, valves for the sink, toilet, and bathtub/shower, and especially at the outside water source.

On 3/28/2026 at 12:28 PM, John_s said:

The guy who installed our water tank with connected pump years ago didnt fit the stop valve inside the tank..Q: can i add a normal ball valve on the pipe between the tank and the pump,or it wouldnt work? Idea is to fill up the water in the evening with the valve closed,and then open it in the morning for use...like now the water thats left in the tank at the end of the day is gone in the morning...and we have slow water supply..

of course you can ... think about this... also install a " Brass to PVC with checkvalve/ Union " so you always have access to make changes without having to cut the pipe down all the time

On 3/28/2026 at 12:49 PM, Yellowtail said:

Exactly, and everyone should have these regardless. I think you have to have them by law.

I think this is correct. It's illegal to have anything from your own tank going into the municipal water supply line. For that reason I'm not permitted to have the valves to my municipal and my well water supplies open at the same time, as they could cross-pollute (the well water pressure is far higher than the crappy municipal trickle, except at night).

On 3/28/2026 at 12:56 PM, John_s said:

Actually we have a toilet leak also..when we flush the water from the toilet sometimes it spill out(just a little bit) on the outside from the latrin tank,what could be the problem?

"latrin tank"? If you mean the septic tank you should check leach pipe outlet, maybe getting blocked.

If you mean at the cistern, a valid answer already.

You loose water, probably from outletsystem of tank.

Possibility, it is going back into community system is rare. In that case your inlet pipe from tank

is all the way down, a long pipe going in tank, the inlet?

Only in that case water from tank can go back in supply system up to point when level in tank is then low.

Depending again on that inlet pipe in tank and of course the flow to your tank. It is gone then. Negative pressure.

Self suction of inlet system. You could shorten the inlet pipe in tank, if possible. Negative point in that is , filling could make some more noise for longer time.

Your tank is completely closed and no inlet regulation? Then pressure of community system is on your tank and can hold pressure? No vent? Then you have building up pressure in tank and it effects the flow.

You already said low flow in.

If your inlet has a level regulation, like a mechanic shut off valve (same sort as in toilet) that one could leak and water is going back. Again it depends on length inlet pipe inside of tank.

Yes you could also place in inlet supply a non return valve.

i can go only by visualize the situation, as I dont know what is there. And there are some options.

Like inside supply pipe or not, long , short. Level regulating valve or not, vent or not , all closed or not.

If leak is in outlet, your house, You ll have to find to fix.

In case of a leak in outlet anywhere, your pump should be switching on and off, quite regular.

A little leak makes pressure low and pump will start, pressure is back and switch off again.

I had that last year, very tiny leak in toilet, almost not noticeable. But pump let me know.

Yes you can place a valve over there, maybe think also the valve should be replaceable once, so working with some screw couplings? If you glue it in and valve gives up then you have problems replacing.

Pipe would get shorter. However if you do that, you start with a valve, you are always then fixed on same size, otherwise the coupling way or glue way dont fit anymore and again you need to do a lot to replace.

But ok you can do "mai pen rai" way.

Plastic valves have not many issues with water quality. The water can be slightly acid and effect live of valve. Even stainless steel, as there is a big variety on those in metal fi maybe you heard 304 or 316.

Here all is brass, but we have water almost PH 7, neutral.

Be aware in Thailand they sell 2 measurements pipe and accessories. English size in inch and metric size in mm. Have the right one ! I know, as I didnt pay attention and costed me a long time of grinding to fit all.

Also be aware you have English and metric sizes in threads ! They also dont fit together.

If you put a valve over there, you must be real sure it is open when you use the pump.

Very (too) long time not open can cause damage to pump, but of course you will find out very quickly.

However using toilet and leaving could cause such a longer time. When you go to toilet in the night, flush and then there is no water anymore, you closed the valve for the night to fill up ! Pump will run dry for long time, get heated and could be damaged.

SO if you use the valve , you should also SWITCH OFF the pump. Be aware of that situation !

On 3/28/2026 at 12:42 PM, John_s said:

Its not a leak,we live in isaan (think djungle) and the village turn of the water nightime..so the water goes back then

PM sent.