Is there a way to reverse siphon- using it to add water?

I know that siphoning removes water and cleans out waste from under the gravel. But in water change, you have to replace the water. However, I haven't gotten it to flow the opposite way. With a bucket of clean water, I placed the siphon in headfirst and the plastic pipe end into the tank. I tried starting the siphon the usual way- bring it out of water and put it back in once the water drains. It didn't work. I would have bubbles coming out from the tank end each time I tried to start, but that was the furthest I got. I tried to hold the bucket above the tank (there isn't any surface I could put it that would be above the tank, so I had to just hold.) No luck. In the end I gave up and did what I normally do- just pour in the water from the bucket directly into the tank.

VioletThePurple said:

I know that siphoning removes water and cleans out waste from under the gravel. But in water change, you have to replace the water. However, I haven't gotten it to flow the opposite way. With a bucket of clean water, I placed the siphon in headfirst and the plastic pipe end into the tank. I tried starting the siphon the usual way- bring it out of water and put it back in once the water drains. It didn't work. I would have bubbles coming out from the tank end each time I tried to start, but that was the furthest I got. I tried to hold the bucket above the tank (there isn't any surface I could put it that would be above the tank, so I had to just hold.) No luck. In the end I gave up and did what I normally do- just pour in the water from the bucket directly into the tank.

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If the bucket is high enough above the tank it will work. Its physics.

There are ways to pump water into the tank using a pump. @Colin_T has a method of doing that.

connorlindeman said:

If the bucket is high enough above the tank it will work. Its physics.

There are ways to pump water into the tank using a pump. @Colin_T has a method of doing that.

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It should've worked, but it didn't.

VioletThePurple said:

It should've worked, but it didn't.

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How high above the tank was it?

Why not directly from the tap? (If it is drinkwater of course)

My system

With my system above once it is primed you can simply just open the two valves to start the syphon and then close valve 2 and open the tap to refill.

VioletThePurple said:

I know that siphoning removes water and cleans out waste from under the gravel. But in water change, you have to replace the water. However, I haven't gotten it to flow the opposite way. With a bucket of clean water, I placed the siphon in headfirst and the plastic pipe end into the tank. I tried starting the siphon the usual way- bring it out of water and put it back in once the water drains. It didn't work. I would have bubbles coming out from the tank end each time I tried to start, but that was the furthest I got. I tried to hold the bucket above the tank (there isn't any surface I could put it that would be above the tank, so I had to just hold.) No luck. In the end I gave up and did what I normally do- just pour in the water from the bucket directly into the tank.

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You should be able to place the bucket on a board placed across the tank. Immerse the entire hose in either the tank or bucket removing all the air (putting the hose in uncoiled and vertically will remove the air). While holding one hose end closed with your thumb (or crimping by folding the end in half), remove that end of the hose from the water and place in the other container of water (tank or bucket) and open the closed end. To stop, lift hose out of tank raising end above the water level in the bucket. Lower again to start or put hose in bucket to quit.


You can practice this with two buckets, one on a chair with water, another on a floor empty or partially full, before you do it on the tank.

Carmen said:

View attachment 164360

Why not directly from the tap? (If it is drink water of course)

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Because I have a shorter siphon, it's not long enough to connect directly to the sink and reach the tank. I can't use a hose either because that's also too far.

As long as the hose has no air, and the lower end is lower than the top water level of the upper vessel, water will flow.

Oblio said:

As long as the hose has no air, and the lower end is lower than the top water level of the upper vessel, water will flow.

View attachment 164381

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That's simple enough for you to say, but when I did that, it didn't work.

I used to do this with a rubber tube. I'd submerge the tube into a bucket of water and then manipulate it so that all the air comes out. This would include holding up both ends of the tube to equal height raising them up so that the tube is as straight as poss with one turn at the bottom, then submersing with both ends up so that air comes out. Multiple times. End with the tube fully submersed.

I'd then raise the bucket to a level above the tank. I'd then take one end of the tube, pinch it between my fingers so that it is closed (putting the finger over the end of a different material tube may work) and then put that end into the tank. Make sure that the other end is still in the bucket, release the end in the tank, and then check the other end in the bucket is in a stable position. Wait. When the water in the bucket starts running out, hold the end in the bucket so that it remains in the water the maximum amount of time. Including tipping up the bucket on an angle.

Sorry if that is complicated. It's easier than it sounds once you've done it a hundred times.

VioletThePurple said:

I tried starting the siphon the usual way- bring it out of water and put it back in once the water drains.

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The siphon tube should not be lifted out of the water at all. The wide part should be moved up and down quickly to start the siphon but the end of the tube must be under water at all times. If it's lifted out of the water it will stop working.

VioletThePurple said:

That's simple enough for you to say, but when I did that, it didn't work.

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Then you weren't doing it correctly. It's simple physics, and the laws of physics apply to you as much as anyone else. Look closely at what you're doing step by step, because you're going wrong somewhere, it's not that physics doesn't work for you.

@VioletThePurple Are you keeping the tank end of the siphon tube under water all the time? Not lifting the tube out of the water for even a fraction of a second?