Water tank cleaning

[bubblegum]

How to clean the inside of a water tank ? Google says I need a wet vacuum but I don't have one of those.

[sometimewoodworker]

59 minutes ago, bubblegum said:

How to clean the inside of a water tank ? Google says I need a wet vacuum but I don't have one of those.

A long hose 2 ½  X the hight of the tank, a bamboo pole about 1 ¼ the hight of the tank. Tie the hose to the bamboo slightly below the end of the pole, get a siphon going and use the bamboo pole to direct it.

[bubblegum]

30 minutes ago, sometimewoodworker said:

A long hose 2 ½  X the hight of the tank, a bamboo pole about 1 ¼ the hight of the tank. Tie the hose to the bamboo slightly below the end of the pole, get a siphon going and use the bamboo pole to direct it.

That just drains the water doesn't it? I want to clean algeaa and such

[brianthainess]

12 minutes ago, bubblegum said:

That just drains the water doesn't it? I want to clean algeaa and such

Does it not have a big removable lid? A pressure washer would work, I presume it has a drain plug. A photo would help. Plastic, stainless, or concrete??? 

[sometimewoodworker]

2 hours ago, bubblegum said:

That just drains the water doesn't it? I want to clean algeaa and such

No it doesn’t, you hold the hose end into the gunk/sand at the bottom and siphon it out. To just drain the tank take out the drain plug near the bottom.
 

The only problem is if the sides of the tank have algae, then you will need a brush on a stick and as high pressure water as you can get, then let it settle for a few days and use the siphon I described above. 

[northsouthdevide]

My friend gives his skinny brother inlaw a hundred baht to climb in and clean it with a hose and a brush once a year. 

[GreasyFingers]

9 hours ago, northsouthdevide said:

My friend gives his skinny brother inlaw a hundred baht to climb in and clean it with a hose and a brush once a year. 

When we bought the house my dear wife did that for all four tanks, bless her heart.

[johng]

On 2/2/2024 at 11:01 PM, northsouthdevide said:

My friend gives his skinny brother inlaw a hundred baht to climb in and clean it with a hose and a brush once a year. 

Be very careful with that  should at least have a person outside paying attention ( not on their phone) that he is ok at all times while in the tank

and also have some forced ventilation.

There have been quite recent stories in the Thai news about employees dying in similar situations due to toxic gases and or electrocution.

[topt]

On 2/2/2024 at 6:13 PM, sometimewoodworker said:

get a siphon going

Forgive my ignorance but how does one do that?

[Daffy D]

11 minutes ago, topt said:

Forgive my ignorance but how does one do that?

The idea of siphoning is that the pipe outside the tank is longer and lower than the pipe inside the tank.

The principle is that the water in the outside pipe is heavier than the water inside the pipe in the tank thereby gravity pulls it out. As long as the outside pipe is lower than the intake of the inside pipe the syphon will work.

 

The normal way to start a syphon, that is filling the whole pipe with water to get the thing flowing is to suck on the outside pipe till the water starts to flow.

 

This is not really practical with large diameter pipe from the tank.

 

What I do is set the whole thing up, then use water pressure from the pump to fill the outside pipe till its full and flowing back into the tank, then remove the pump and water should start to flow by it's self from the tank.

 

 

 

[sandyf]

On 2/2/2024 at 6:45 PM, bubblegum said:

That just drains the water doesn't it? I want to clean algeaa and such

I got a piece of steel tube, flattened the end and stuck it on the end of the hose. A bit like a pressure washer and blew the sediment out through the drain hole. Also cleaned off most of what was on the walls.

Algae needs sunlight to develop so take it you have a plastic tank. You should shade the tank which will also make it last longer as the UV in the sunlight makes the plastic deteriorate. A drop of bleach in the tank now and again will also deter algae growth.

[sandyf]

On 2/2/2024 at 11:01 PM, northsouthdevide said:

My friend gives his skinny brother inlaw a hundred baht to climb in and clean it with a hose and a brush once a year. 

Even matchstick men wouldn't get through the caps on our plastic tanks, wife goes inside the concrete ones.

[topt]

2 hours ago, Daffy D said:

The idea of siphoning is that the pipe outside the tank is longer and lower than the pipe inside the tank.

The principle is that the water in the outside pipe is heavier than the water inside the pipe in the tank thereby gravity pulls it out. As long as the outside pipe is lower than the intake of the inside pipe the syphon will work.

 

The normal way to start a syphon, that is filling the whole pipe with water to get the thing flowing is to suck on the outside pipe till the water starts to flow.

 

This is not really practical with large diameter pipe from the tank.

 

What I do is set the whole thing up, then use water pressure from the pump to fill the outside pipe till its full and flowing back into the tank, then remove the pump and water should start to flow by it's self from the tank.

 

 

 

Thanks but note second part which is why I was asking -

On 2/2/2024 at 9:21 PM, sometimewoodworker said:

No it doesn’t, you hold the hose end into the gunk/sand at the bottom and siphon it out. To just drain the tank take out the drain plug near the bottom.

I wasn't sure how to "suck"out the sand especially as there is nowhere lower than the bottom level of the tank - well maybe 2 inches if that.....

[Fruit Trader]

Above ground tank cleaning

 

Our product wash supply tanks are cleaned three times a year using strong chlorine and brush. To make this an easy task all pipe connections are fitted with barrel unions which allow the tank to be quickly disconnected tipped on its side for cleaning and upside down to drain and rinse. 

 

 

PVC inline barrel union.

 

[Daffy D]

 

5 hours ago, topt said:

Thanks but note second part which is why I was asking -

I wasn't sure how to "suck"out the sand especially as there is nowhere lower than the bottom level of the tank - well maybe 2 inches if that.....

 

My tank is up a 60m tower so the syphon thing works well. It does suck out all the gunk.

 

If you tank is only a few inches off the ground you need the outside hose to be a lot longer to get that weight of water for the syphon to work. If possible even put the end down a drain to get that extra height.  

 

Inspired by this thread I finally got round to cleaning my tank today.  I had the end of the drain hose somewhere I could see while up the tower so knew where to poke the suction pipe. 

 

Los of gunk came out, so should be good for another few years.

 

[sometimewoodworker]

5 hours ago, topt said:

I wasn't sure how to "suck"out the sand especially as there is nowhere lower than the bottom level of the tank - well maybe 2 inches if that.....

Physics: The hight of the water level in the tank (usually about 1.5 meters +) above the outlet is the thing governing if the siphon is going to work, not the location of the bottom of the inflow tube. 

I’m not going to give a lecture on physics, the fact is that it will function.

try the experiment for yourself, it’s simple enough if you use a small dimeter pipe, less than ½” for the experiment, probably more than 1” for the cleaning pipe

 

FWIW the bottom of the column of water (your tank) can be far below the outlet pipe, with the inlet pipe well below the the level of the outlet pipe and it still functions and the siphon still siphons 

 

EDIT as @Daffy D said a greater hight between the top of the water column and the bottom of the outflow will work better. 10 meters = 1 ATM or 1 bar of pressure. 
 

Also he needed the extra hight as he severely restricted the flow by using a small diameter flexible pipe. It worked so all is good

[Phantom57]

“60 m tower”, sure, great pressure.

[sometimewoodworker]

3 minutes ago, Phantom57 said:

“60 m tower”, sure, great pressure.

6 bar!!  It should probably be 0.6 bar and a 6 metre tower😇

but maybe he is also the control tower for the airport 

[Daffy D]

Opps! Supposed to be 6m.

 

Still great suction  

[topt]

3 hours ago, sometimewoodworker said:

I’m not going to give a lecture on physics, the fact is that it will function.

Please bear with me as I was not disputing that. I was querying how to set it up especially as  @Daffy D now talks about fixing a pump to start things off..........I think I once many moons ago syphoned out petrol and that sucked.........

 

What I was also hoping to do was to use up most/half of the water in the tank before trying to syphon out the sand in the bottom - or is that not possible?

It is a DOS 1000L tank so 180cm high.

 

OK sorry @sometimewoodworker just reread your earlier reply to someone else so clearer to me now thanks 

[sometimewoodworker]

28 minutes ago, topt said:

What I was also hoping to do was to use up most/half of the water in the tank before trying to syphon out the sand in the bottom - or is that not possible?

It is a DOS 1000L tank so 180cm high.

Don’t do it.
 

The fuller the tank the better it works the full tank is 2.6 psi the half empty one is about 1.2 psi siphon pressure.

use a minimum of a 1.5” pipe as a small one kills on friction losses. A ½ pipe is about 80X worse than a 1 ½ one.

 

the only time you run the tank down is before taking the drain plug out and that doesn’t do much if anything for cleaning gunk.
 

@Daffy D has about 8+ psi

[sometimewoodworker]

2 minutes ago, sometimewoodworker said:

Don’t do it.

 

[Daffy D]

Daffy D now talks about fixing a pump to start things off..........I think I once many moons ago syphoned out petrol and that sucked.........

 

Not sure if I explained it right. The idea of the pump is to attach it to the end of the outlet pipe. Fill the whole pipe with water using the pump, right up until the water flows back into the tank. When the whole pipe is full of water remove the pump and the syphoning should start.

 

Of course you always suck on the end, like syphoning petrol, but in this case I think using the pump would be better.  

[sometimewoodworker]

10 hours ago, Daffy D said:

Of course you always suck on the end, like syphoning petrol,

If you are using a 1½” (the best pipe size to reduce friction but going bigger doesn’t reduce friction losses by much) sucking to start the siphon is going to be a really interesting experience, so filling the pipe a different way is going to be required. 

[Daffy D]

45 minutes ago, sometimewoodworker said:

If you are using a 1½” (the best pipe size to reduce friction but going bigger doesn’t reduce friction losses by much) sucking to start the siphon is going to be a really interesting experience, so filling the pipe a different way is going to be required. 

I was going to make some joke about auditioning bar girls for the job but decided it wasn't really my thing 

 

Anyway that's the object of using a pump to fill the pipe with water.

 

[sometimewoodworker]

3 hours ago, Daffy D said:

 

Anyway that's the object of using a pump to fill the pipe with water.

 

Have you tried filling a pipe that size by sucking on it? 
 

I know for sure I can’t, and I doubt that even the most talented BG has the lung capacity.

[topt]

On 2/9/2024 at 9:25 AM, Daffy D said:

Anyway that's the object of using a pump to fill the pipe with water.

Could I use a hosepipe? Otherwise I have no pump and short of buying one cannot see any other way to achieve the result required. 

[Daffy D]

10 hours ago, topt said:

Could I use a hosepipe? Otherwise I have no pump and short of buying one cannot see any other way to achieve the result required. 

Yes

You can use pressure from the village water to fill the pipe. Doesn't matter what you use just need to get the pipe filled with water.

 

Get the syphoning hose set up. One end inside the tank near the bottom and the longer section outside lower as much as possible than the intake of the inside hose.

 

Connect the village water supply to the end of the outside hose and let it run till you can feel/see the water coming out of the hose inside the tank. The whole hose is now full of water and by removing the village water hose the syphoning should start to empty the tank.  

 

To suck up the sediment collected at the bottom of the tank you will need to use a stiff pipe to move around the bottom of the tank, a flexible hose would not work. I use a length of that blue plastic pipe.

 

If your tank is on the ground and you don't have much drop for the syphoning to work, make sure the outside hose quite long and laying on the ground, you need more weight of water in the outside hose than in the inside hose for it to work. Sticking the end of the outside hose down a drain would help to get stronger flow of water.

 

I use a 3/4 pipe, because that's what I happen to have, but any size will work, though bigger is better.

 

Good luck  

 

If you only have flexible hosepipe you could attach the section that goes into the tank to a long stick and poke around with that, that would work.  

 

 

 

[sometimewoodworker]

12 hours ago, topt said:

Could I use a hosepipe? Otherwise I have no pump and short of buying one cannot see any other way to achieve the result required. 

It seems that you really don’t understand how a siphon functions and don’t know to start one. You don’t need a pump.

 

no a hose pipe is not going to work or is going to work badly as the pipe is too small diameter 

 

STEP 1

fill the tank to 100%

fill the 1 ½ pipe to 100% any way of filling it works 

 

STEP 2

get someone to hold one end of the pipe higher than the tank.

Use your hand to block off the other end of the pipe so that little air enters 

put that end of the pipe under water in the tank

STEP 3

put the end of the hose in the tank just above the gunk level 

get the person who has been holding the other end of the hose to put it below the bottom of the tank 

using your bamboo pole put the tank end into the gunk you will have a flow of several litres per minute of watery gunk

 

REPEAT steps 1~3 until it works. Keep filling the tank.

 

as a wise man said “I can explain it to you but I can’t understand it for you

2 hours ago, Daffy D said:

I use a 3/4 pipe, because that's what I happen to have, but any size will work, though bigger is better.

 

Good luck  

Though what @Daffy D said is strictly true, in practice it isn’t 

A ¾” hose will be poor without a significant hight difference (the OP only has about 1~1.8 meters) 

 

For that small a differential you need at least 1” but 1.5” is better bigger than that doesn’t make enough difference to matter.

[Daffy D]

Didn't know the basic simple task of syphoning could be so complicated  

 

Love the artwork.  Just to clear up a point, you have to move the suction end in the tank around the bottom to get the gunk, leaving it in just one place will only suck a hole in the gunk, it has to be moved around.

 

Another way of filling the syphon hose is to shove the whole hose into the tank so it gets full of water. Block the end, so the water doesn't run back into the tank as you quickly whip the hose out and lay it on the floor. If it's done right the syphoning should start.

 

It's how I empty the kids paddling pool, using a 1/2 hose with my thumb over the end. Works every time.