Return line at bottom of display tank?

[Eldy]

I have a chance to run the return lines from the sump to the bottom of the tank.

Is there any reason to do this or is it total over kill in insuring the freshly treated water is returned to the display tank at the bottom of the tank as far away from the overflow as possible.

Don't worry about the reverse siphon if there is a power outage.

 

[Big Smelly fish]

If power goes out it could flood , I don’t think they make a foolproof check valve.
I miss the last line of your post.

 

[watdachuck]

Overkill, but I'm intrigued.

 

[Eldy]

If i did this i would drill the sump for an emergency 2" overflow strait into the basement into a spare recovery tank... Plus i am working on getting a inline generator for the house that kicks in under 2 seconds.

I have also seen some crazy emergency valves at the place i work that require us to provide a constant 120V circuit to them and if the power stops the gate valve slams shut. Basically it is a high spring rate spring on the back of a gate valve and a solenoid that holds it open when power is applied.

Kinda thinking of building the outlets into rocks. Maybe even one that looks like an underground vent. Just wasn't sure if the corals/sea life would freak out from a continuous flow from the sea bed?
Got to figure out how to hide the down pipes on the inside of the tank also....

 

[MaddyP]

Mine is all in the bottom of my tank…

 

[JNalley]

Kinda thinking of building the outlets into rocks. Maybe even one that looks like an underground vent. Just wasn't sure if the corals/sea life would freak out from a continuous flow from the sea bed?
Got to figure out how to hide the down pipes on the inside of the tank also....

They should not freak out from continuous flow from the sea bed, the ocean has flow from top to bottom, and most currents are actually really deep.

Hiding the downpipes should be just like hiding the return (with rock). Check out @Lasse 's build thread, he has a neat-looking rock wall in his scape, something I am going to try and replicate, though I want mine to be more organic (Holes, caves, etc) and look more like reef rock, I am planning to do it to my new tank by making my own rock wall using mortar, aragonite sand, shells, etc and then curing it as you would any other man-made rock.

Edit: wait, do you mean pointing straight upwards instead of horizontally? That I don't know if fish would freak out...

 

[homer1475]

Would be no different then a closed loop system that had return nozzles down low.

Like said though, my only worry would be when the power fails.

 

[Lasse]

Is there any reason to do this or is it total over kill in insuring the freshly treated water is returned to the display tank at the bottom of the tank as far away from the overflow as possible.

Don't worry about the reverse siphon if there is a power outage.

Whats the reasons why you want the return to go through your bottom? To hide pipes?

Look at this solution

When I get a power stop - air will be sucked in nearly instantly and form an air lock for further reversed siphon. If you want a bottom outlet too - just dived the the inlet pipe directly after the highest point (that need to be higher than your surface) - pump - tube - highest point (over the surface)

The principle

The way I did it

Suggestion for you

Sincerely Lasse

 

[Eldy]

The reason i am even contemplating this is because i would like to give the wild life a good home with the best flow and water movement i can give them. I was thinking if i can get the flow down low to the bottom it would cause a nice up current that would pull the junk off the floor of the tank and pull it into the overflow. Thus giving me more of a true turn over of the complete water in the tank. Might be able to use less power heads.

As for the direction of the output that i might run one of those three way multi-head jobbers to control the direction of the flow.

Some of the want is to pull the junk off the floor so i don't have to work as hard. Right now i have the tank setup with some freshwater green phantom pelcos, a rainbow shark, four yaya loches and a bunch of golden tetra's. Crud for lack of a better word just seems to hang on the bottom of the tank.



The tank has four 1 inch return bulk heads thru the back of the tank. So i was thinking of Lasses last idea and run the reverse P trap on the outside of the tank, so the back of the tank hides the ugliness.

 

[Rmckoy]

My previous tank ( 90 gal ) was like this. .

the tank was drilled on the bottom
It worked great , the plumbing can all be hidden .
when plumbing make sure to install a directional check valve And the right way .
when power shuts off the flap closes completely .
If you have a light in your sump shade this section as you don’t want any algae growing in it .
shells , snails or anything that can potentially get lodged and cause it to stay open .

I’ve never had a problem running it for 5+ years .
That tank started to leak in the opposite corner which was the reason for the recent upgrade

 

[Spieg]

So in the worst case, the water goes to the sump and then to a holding tank in the basement... What about your fish and coral that don't have any water?

 

[Eldy]

Spieg that would be a worse case situation if the Generator Never turns on. Also if you slide a T into the down line after the bulk head and reduce it down to say a 1/4 or 1/2 inch opening and throw a mini head on there the minute that line would suck air the siphons would stop.

Trust me i have done the oh crap i have flooded the sump with a reverse siphon. The thing that sucked was that was a little 20 gallon sump. So there was not much spare room only about 5-7 gallons. Let me tell you at that moment the only thing in your head is oh snap how do i stop this. Luckly it was direct result of some maintenance i was messing the overflow and turned the pump off. So i just turn the sucker on and let it empty the sump.

I have also tested if a single pump fails and the check valve stays open. One pump is able to keep the water flowing to the tank to keep the primary drain running, in the event of a single pump failure and a siphon stays running. Plus if it does start a reverse siphon i found out the return lines make a horrific rattling/banging noise due to the minimal amount of anchor points on the returns. But they are stone dead quiet when it is running with the right direction.

But the real question comes down to is all the contingency planing and setup worth having the returns on the bottom of the tank or just stay with the tried and true method??

 

[Spieg]

I must be missing something... when there is a line connected to the bottom of the tank, where is the siphon? Seems like there would be positive pressure so long as there is water in the tank?

 

[Lasse]

I must be missing something... when there is a line connected to the bottom of the tank, where is the siphon? Seems like there would be positive pressure so long as there is water in the tank?

It is the pipe from the return pump

Sincerely Lasse

 

[Spieg]

It is the pipe from the return pump

Sincerely Lasse

So is the return pump above the water level in display tank? Still don't see where siphon figures into the system.

 

[CollectOyster04]

In case of a power failure, generator failure, and/or check valve failure, your return pipe (connected to your pump in your sump) would effectively create a siphon and drain your tank to the return pipe's level in the display. It's a lot of "What if's", but it has happened to more than one person hence why you don't see many tanks designed this way. Too many points of failure for most likings. Not saying there aren't people running tanks like this who have never experienced a problem, but it's more of risk tolerance. If you have thousands if not tens of thousands of dollars of livestock, is it worth that much perceived risk ? A regret could be costly. Not to mention any potential water damage to your dwelling. I'm sure most of us at one time thought we had a good contingency plan until we didn't.
A safer bet may be a closed loop system instead if power heads are not an option. In the end, it's all about the potential risk you're willing to take to gain any perceived reward.

 

[Lasse]

In case of a power failure, generator failure, and/or check valve failure, your return pipe (connected to your pump in your sump) would effectively create a siphon and drain your tank to the return pipe's level in the display. It's a lot of "What if's", but it has happened to more than one person hence why you don't see many tanks designed this way. Too many points of failure for most likings. Not saying there aren't people running tanks like this who have never experienced a problem, but it's more of risk tolerance. If you have thousands if not tens of thousands of dollars of livestock, is it worth that much perceived risk ? A regret could be costly. Not to mention any potential water damage to your dwelling. I'm sure most of us at one time thought we had a good contingency plan until we didn't.
A safer bet may be a closed loop system instead if power heads are not an option. In the end, it's all about the potential risk you're willing to take to gain any perceived reward.

Right . however - the constructions I show in my drawings - all stop the siphon when the upper outlet suck in air (blue marking) even if you have a bottom outlet. It will form an air bubble in the highest part (red marking). Its more safe than a check valve.

Sincerely Lasse