Keeping A Canister Filter From Draining The Tank?

I bought a used Eheim canister filter and it works great, but when it loses power and the pressure inside the canister changes it leaks. If power is not restored the filter will continue to suck out water without returning it into the tank and end up draining it.
The guy that I purchased it from said it had always done that so he just left it in a large plastic bin.
We have a huge storm forecast for today and tomorrow, and my power goes out at the drop of a hat sometimes. Luckily my dad is home today to close off the valves if the power goes out, but tomorrow my house will be empty for a majority of the morning.
Has anyone had a similar problem?
Is there a way to keep the filter from leaking or to at least prevent the tank from draining?

 

Have you replaced the o-ring? Sounds like it might be an o ring issue.

Otherwise, consider modifying the input so its close to the water surface (or drilling a small hole in the input near the surface) so when the power does break, the tank doesn't drain that much. The only issue is, once the power turns back on, the tank will not have enough water to run the filter properly...

 

I bought a used Eheim canister filter and it works great, but when it loses power and the pressure inside the canister changes it leaks. If power is not restored the filter will continue to suck out water without returning it into the tank and end up draining it.
The guy that I purchased it from said it had always done that so he just left it in a large plastic bin.
We have a huge storm forecast for today and tomorrow, and my power goes out at the drop of a hat sometimes. Luckily my dad is home today to close off the valves if the power goes out, but tomorrow my house will be empty for a majority of the morning.
Has anyone had a similar problem?
Is there a way to keep the filter from leaking or to at least prevent the tank from draining?

I would also try replacing the o ring. Put it in a large tote and if it continues its probably a defective filter hopefully you didn't pay to much for it.

 

Most likely an o-ring issue as many are saying. I’ve heard of people making their own silicone o ring that they simply replace every time they open the canister but it seems unnecessarily difficult to me rather than just investing in a new filter. As others have said modifying the input should help but also take into account that the output will often suck in water as well

 

It certainly sounds as though the O-ring maintains a good seal while the filter is running and pressurized, and then when the pressure drops the O-ring "relaxes" and allows water to drain out while the tank merrily siphons itself empty. I would suggest opening up the filter and carefully examining both the ring itself and the channel or groove in which it seats. If the ring is damaged, replace it. Look carefully for some bit of dirt in the groove, or even an irregularity in the plastic, which might cause the damage. Changing O-rings regularly will be far cheaper than a new filter; do you buy a new car every time your tires wear out?

As a back-up safety, a small hole in both the intake and return lines, situated in the tank and just below the surface of the water, will cause the siphon to break and limit the amount of water which is lost. It shouldn't lock up the pump, since an air bubble will collect in the high point of each line, i.e. where it passes over the top rI'm of the tank rather than filling the cannister. Make sure the hole is far enough below the water level so that it doesn't suck air constantly while the pump is running.

This problem is no doubt irritating, but it sounds like it should be a pretty simple fix if you approach it logically and rationally. Good luck!

 

When I first tried setting it up it leaked continuously while on until I cleaned out the o-ring. It may still need to be replaced, I’ll look into it this afternoon.
When I got the filter I paid $100, and it also came with a tank, stand, medications/foods/decor and all sorts of equipment. I got a really good deal on everything so I won’t be too upset if I need to replace a thing or two haha.

 

When I first tried setting it up it leaked continuously while on until I cleaned out the o-ring. It may still need to be replaced, I’ll look into it this afternoon.
When I got the filter I paid $100, and it also came with a tank, stand, medications/foods/decor and all sorts of equipment. I got a really good deal on everything so I won’t be too upset if I need to replace a thing or two haha.

Definitely sounds like you got a good deal. I would say maybe 15-20 bucks if baught separately so if it does need to be replaced you basically only paid for the tank.

 

ooohhh, the O-Ring, I bought mine second hand knowing it leaks slightly when its switched off/on again, this post was a nice luck to stumble on thank you!

 

It simply shouldn't leak (with or without power).

 

It simply shouldn't leak (with or without power).

Pro advice!

 

Pro advice!

Hahahaha. I know.
But what I meand to say one shouldn't tske risks with leaking canisters. the sollution of the seller to place it in a bin sounds ridiculous to me (it prevents water on the ground, but doesn't prevent syphoning the tank).

I've once bought a filter that appeared to be leaking. Wished the buyer to meet the right "Karma" and binned it.

 

Hahahaha. I know.
But what I meand to say one shouldn't tske risks with leaking canisters. the sollution of the seller to place it in a bin sounds ridiculous to me (it prevents water on the ground, but doesn't prevent syphoning the tank).

I've once bought a filter that appeared to be leaking. Wished the buyer to meet the right "Karma" and binned it.

I personally don't recommend buying second hand faulty things that serve an important service, in the case of my purchase, I wanted the tank and lights and the was like "I'm going to throw th is away, it just drips a teacup of water when it's turned off" and well, I took it and looking at these posts it looks like I got a 250gph canister filter for the price of a new seal

 

I like my Eheim canister filters, they're quiet and dependable and they rarely need to be serviced. One thing I do NOT like about them though is the clasps that hold the pump head to the canister. (I'm talking on the Classic line of filters, I only own this line).
If the manufacturing was off by even a bit then the clasps can "relax" enough to allow the water pressure to lift the top up off of the canister and begin leaking/siphoning. I'm talking about when the unit is de-energized, like when the power goes out.
I had to return the very first one that I bought that had this happen - flooded my living room floor. Luckily I was doing my first ever water change on my new tank and caught it fairly quickly but not before I had a soaked carpet.
It could be a bad O-ring or it could be that the clasps simply do not latch securely enough when the canister is full. It won't present itself while the pump is running but yeah, don't turn it off.
I've bought more Eheims since that first one but I've inspected them closely before using and closely watched them until I felt comfortable that they were performing properly.
Good luck!

 

I like my Eheim canister filters, they're quiet and dependable and they rarely need to be serviced. One thing I do NOT like about them though is the clasps that hold the pump head to the canister. (I'm talking on the Classic line of filters, I only own this line).
If the manufacturing was off by even a bit then the clasps can "relax" enough to allow the water pressure to lift the top up off of the canister and begin leaking/siphoning. I'm talking about when the unit is de-energized, like when the power goes out.
I had to return the very first one that I bought that had this happen - flooded my living room floor. Luckily I was doing my first ever water change on my new tank and caught it fairly quickly but not before I had a soaked carpet.
It could be a bad O-ring or it could be that the clasps simply do not latch securely enough when the canister is full. It won't present itself while the pump is running but yeah, don't turn it off.
I've bought more Eheims since that first one but I've inspected them closely before using and closely watched them until I felt comfortable that they were performing properly.
Good luck!

I will look at this as soon as I'm home, the guy DID say that it leaked only when putting it off from the very beginning, fasten the lid again and then no leaking until the next time it was powered down.

 

One thing I do NOT like about them though is the clasps that hold the pump head to the canister. (I'm talking on the Classic line of filters, I only own this line).
If the manufacturing was off by even a bit then the clasps can "relax" enough to allow the water pressure to lift the top up off of the canister and begin leaking/siphoning

Any time I remove the top of mine, I bend those little clamps a bit to make them more secure. Have found they can loosen themselves over time.

I agree with the posts above, drop small hole in the intake tube just below the water surface.

 

until you get that new O ring, you can put the canister on a stand so that it sits a little higher than the tank. if the power goes out gravity will pull the water down from the canister and into the tank.

 

until you get that new O ring, you can put the canister on a stand so that it sits a little higher than the tank. if the power goes out gravity will pull the water down from the canister and into the tank.

That's impossible. A canisterfilter should be under water/tanklevel. It only pumps the water up/out and is syphoning in (vacuum / gravity) Law of the commjnicating vessels also has its influence.

A cannister above waterlevel won't work / run dry / overheat.

 

ok, nvm then. I thought they pumped water in and out.

 

That's impossible. A canisterfilter should be under water/tanklevel. It only pumps the water up/out and is syphoning in (vacuum / gravity) Law of the commjnicating vessels also has its influence.

A cannister above waterlevel won't work / run dry / overheat.

Sorry, no, that absolutely will work. When a canister filter is first set up and filled, keeping it below the water level in the tank makes it much easier to start filling it by siphoning the water in. Once the filter is filled and turned on it becomes a closed system and you can easily lift it up and set it on a higher level. When I used canisters in the past (Fluvals and Eheims) I routinely placed them that way and they operated for years without problems.

I've also had a tank set up for turtles which was only filled a little over halfway. It was filtered by a canister filter called a H.O.T. (hang on tank)...I don't remember the maker; Marineland, maybe? When suspended from the lip of the tank, it was also entirely above the water level and functioned perfectly. I'm a retired electrician; there's nobody more paranoid about overheating wires and electrical gear around water than me.

The only danger with this plan is that a power outage, combined with the poor sealing O-ring, will allow the water to siphon back into the tank, rather than from the tank to the filter and then to the floor. This saves your carpet, but when the power returns the filter will be running dry and will burn out. You can avoid this by purchasing a Fail Safe extension cord. This acts like a circuit breaker, but instead of "popping" when there is an overcurrent or a ground fault, it turns off automatically when the power goes out. Then, when power is restored, it requires you to manually re-set it (i.e. just press the button on it) before the filter will re-energize. That will give you a chance to inspect your filter and ensure that it is full of water before it is turned back on. It's important to keep a drip-loop in the power cord so that if water runs down the cord for some reason, it reached a low spot and drips off before it reaches the receptacle...that would be a bad thing.

Believe me, a new O-ring is the cheapest solution...but if you are a pants-and-suspenders kind of guy like me, a Fail-Safe device, plugged into a proper GFCI-protected receptacle to power all your aquarium gear is a great comfort.

 

Sorry, no, that absolutely will work. When a canister filter is first set up and filled, keeping it below the water level in the tank makes it much easier to start filling it by siphoning the water in. Once the filter is filled and turned on it becomes a closed system and you can easily lift it up and set it on a higher level. When I used canisters in the past (Fluvals and Eheims) I routinely placed them that way and they operated for years without problems.

I've also had a tank set up for turtles which was only filled a little over halfway. It was filtered by a canister filter called a H.O.T. (hang on tank)...I don't remember the maker; Marineland, maybe? When suspended from the lip of the tank, it was also entirely above the water level and functioned perfectly. I'm a retired electrician; there's nobody more paranoid about overheating wires and electrical gear around water than me.

The only danger with this plan is that a power outage, combined with the poor sealing O-ring, will allow the water to siphon back into the tank, rather than from the tank to the filter and then to the floor. This saves your carpet, but when the power returns the filter will be running dry and will burn out. You can avoid this by purchasing a Fail Safe extension cord. This acts like a circuit breaker, but instead of "popping" when there is an overcurrent or a ground fault, it turns off automatically when the power goes out. Then, when power is restored, it requires you to manually re-set it (i.e. just press the button on it) before the filter will re-energize. That will give you a chance to inspect your filter and ensure that it is full of water before it is turned back on. It's important to keep a drip-loop in the power cord so that if water runs down the cord for some reason, it reached a low spot and drips off before it reaches the receptacle...that would be a bad thing.

Believe me, a new O-ring is the cheapest solution...but if you are a pants-and-suspenders kind of guy like me, a Fail-Safe device, plugged into a proper GFCI-protected receptacle to power all your aquarium gear is a great comfort.

Mmmm okay. First time I hear this and to my knowledge most brands mention in their manuals they should below waterlevel (will search later)

As said a filter isn't designed to suck water in but only to pump.water out. Vacuum and gravity do the rest. In your case only the vacuum works.

BTW if the canister leaks that could mean if.placed that way, it will suck in air (by the same O-ring) instead of leak water so the vacuum won't be their anymore.

But you experienced make me think, which is awesome hahaha

 

Mmmm okay. First time I hear this and to my knowledge most brands mention in their manuals they should below waterlevel (will search later)

As said a filter isn't designed to suck water in but only to pump.water out. Vacuum and gravity do the rest. In your case only the vacuum works.

BTW if the canister leaks that could mean if.placed that way, it will suck in air (by the same O-ring) instead of leak water so the vacuum won't be their anymore.

But you experienced make me think, which is awesome hahaha

That's what I like about this forum,
everyone gives their experiences and we pick and choose what works for us. I for one will rather fix the pump or get a new one than take a chance with "MacGyver fixes", it's my little finned babies lives I'm playing with after all!

With my "free" filter, if I service it, change the seal, fiddle with the clamps and it STILL leaks mildly then I'd rather just buy a new one.

 

That's what I like about this forum,
everyone gives their experiences and we pick and choose what works for us. I for one will rather fix the pump or get a new one than take a chance with "MacGyver fixes", it's my little finned babies lives I'm playing with after all!

With my "free" filter, if I service it, change the seal, fiddle with the clamps and it STILL leaks mildly then I'd rather just buy a new one.

MacGyver would make a completely new canister from a paperclip and a bucket in an instant !!!

 

MacGyver would make a completely new canister from a paperclip and a bucket in an instant !!!

Right? Sadly I'm not that talented

 

ooohhh, the O-Ring, I bought mine second hand knowing it leaks slightly when its switched off/on again, this post was a nice luck to stumble on thank you!

I bought my 4 replacement O rings from a local (ACE) hardware store for $0.33 cents each instead of the $10.00 they would have cost me at the fish store. Just take the worn ones with you so you get the right size! I get my hoses, tubing and many other replacement items there as well. MUCH cheaper, identical stuff.

 

Mmmm okay. First time I hear this and to my knowledge most brands mention in their manuals they should below waterlevel (will search later)

As said a filter isn't designed to suck water in but only to pump.water out. Vacuum and gravity do the rest. In your case only the vacuum works.

BTW if the canister leaks that could mean if.placed that way, it will suck in air (by the same O-ring) instead of leak water so the vacuum won't be their anymore.

But you experienced make me think, which is awesome hahaha

It will absolutely suck in air, breaking the siphon action and preventing water from entering/leaving the inert filter. That's the plan.

Back when dinosaurs ruled the earth, canister filter instruction manuals suggested that their products could be placed above, below or level with the water level in the tank; it was one of their numerous selling points. Quite possibly the lawyers have gotten hold of this notion and put an end to it...but that doesn't change the laws of physics. The idea works. Here in Canuckistan, all the wonderful submersible aquarium heaters that we take for granted are equipped with instruction manuals that expressly forbid placing them underwater! Liability, liability, liability...

If this concerns you, bear in mind that we are not talking about placing the filter ten feet into the air. Situate it so that the leaky O-ring is just an inch or two above the water level in the tank. This is sufficient to prevent water from moving from tank to filter...to floor!

 

It will absolutely suck in air, breaking the siphon action and preventing water from entering/leaving the inert filter. That's the plan.

Back when dinosaurs ruled the earth, canister filter instruction manuals suggested that their products could be placed above, below or level with the water level in the tank; it was one of their numerous selling points. Quite possibly the lawyers have gotten hold of this notion and put an end to it...but that doesn't change the laws of physics. The idea works. Here in Canuckistan, all the wonderful submersible aquarium heaters that we take for granted are equipped with instruction manuals that expressly forbid placing them underwater! Liability, liability, liability...

If this concerns you, bear in mind that we are not talking about placing the filter ten feet into the air. Situate it so that the leaky O-ring is just an inch or two above the water level in the tank. This is sufficient to prevent water from moving from tank to filter...to floor!

My fluval says that the canister MUST sit at least 7.5 inches BELOW the aquarium water line. Check your manual before raising your canister....