How about over three neighbors?
Many thanks for all the responses. I'm torn between this (practical) and building a 6' long 75g for the same spot (not so practical).
You were all supposed to say "No don't do it there will be water everywhere".
Two tanks, one filter ? best approach?
- Thread starter carpguy
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How about over three neighbors?
Many thanks for all the responses. I'm torn between this (practical) and building a 6' long 75g for the same spot (not so practical).
You were all supposed to say "No don't do it there will be water everywhere".
Why do you think when I built this house the tank room is a step down and waterproof? 
That where the circulating range is...
That where the circulating range is...
Maybe I'm just retarded but I dont understand how the siphon works. How do you get it to flow in the right direction? What if the siphon is stronger than the filter suction and fills the tank faster than the intake can handle? Won't you flood the floor? If someone can explain this system to me in detail (dumbed down) I'd be greatful.
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One tank has the outflow to the filter, one tank has the return from the filter.
The two tanks are connected by a U-shaped tube that's been filled with water and has both ends well below the surface of each tank. This is the siphon.
As water starts to exit the outflow tank the water level begins to drop, creating a lower pressure on that side of the siphon. At about the same time water starts entering the return tank, raising the pressure on that side. This causes water to flow through the siphon from the return tank to the outflow tank to keep the pressure (and water levels) equal on both sides. The rate and direction of flow through the siphon is controlled by the flow to and from the filter — its a system trying to maintain equilibrium.
The big concern is: what happens if the siphon were to ever break (air bubbles collecting in it over time) or clog? (The outflow tank would empty out and not quite half the water in the system would flood over the sides of the return tank, at which point the filter would run dry and you'd burn out the pump -- all very bad things
).
You'll notice most of the posts address these two things, siphon breaks and clogging. RTR has a very clever bleed-off and along with OG favors redundancy. Somefinnfishy mentions keeping the tubes short to minimize the flooding in the worst case scenario. Somewhere in my searching on this I came across someone who mentioned drilling a small siphon-breaking hole near the top of the outflow tube so that if the water level on the outflow tank dropped too far the siphon to the filter would be broken before all that many gallons got out over the side. Somefinn also mentions using an overflow box, which would likewise help minimize potential flooding by limiting the outflow.
It seems to me that there are enough solutions to the potential problems and I'm mostly leaning towards trying a two-tank setup at this point.
The two tanks are connected by a U-shaped tube that's been filled with water and has both ends well below the surface of each tank. This is the siphon.
As water starts to exit the outflow tank the water level begins to drop, creating a lower pressure on that side of the siphon. At about the same time water starts entering the return tank, raising the pressure on that side. This causes water to flow through the siphon from the return tank to the outflow tank to keep the pressure (and water levels) equal on both sides. The rate and direction of flow through the siphon is controlled by the flow to and from the filter — its a system trying to maintain equilibrium.
The big concern is: what happens if the siphon were to ever break (air bubbles collecting in it over time) or clog? (The outflow tank would empty out and not quite half the water in the system would flood over the sides of the return tank, at which point the filter would run dry and you'd burn out the pump -- all very bad things
). You'll notice most of the posts address these two things, siphon breaks and clogging. RTR has a very clever bleed-off and along with OG favors redundancy. Somefinnfishy mentions keeping the tubes short to minimize the flooding in the worst case scenario. Somewhere in my searching on this I came across someone who mentioned drilling a small siphon-breaking hole near the top of the outflow tube so that if the water level on the outflow tank dropped too far the siphon to the filter would be broken before all that many gallons got out over the side. Somefinn also mentions using an overflow box, which would likewise help minimize potential flooding by limiting the outflow.
It seems to me that there are enough solutions to the potential problems and I'm mostly leaning towards trying a two-tank setup at this point.
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Thank you Carpguy. If my understanding is correct, both sides of the U connector must be the same length to keep equlibrium?
The two sides of the U don't necessarily need to be the same length. Once an arm breaks the plane of the surface it becomes part of that tank.
Think water change buckets. If the bucket is lower than the tank the water flows to it. If the bucket is higher the water flows from it. If the water level in the bucket is the same as the tank, water stops flowing back and forth and the siphon just sits and holds. The length of tube on either side isn't important so long as the intake side stays submerged (if the system is at equilibrium that means both sides).
Think water change buckets. If the bucket is lower than the tank the water flows to it. If the bucket is higher the water flows from it. If the water level in the bucket is the same as the tank, water stops flowing back and forth and the siphon just sits and holds. The length of tube on either side isn't important so long as the intake side stays submerged (if the system is at equilibrium that means both sides).
this is probably a dumb idea, but its something i was thinking of when i set up my tank rack. with a good canister filter, you can buy the Y valves and then you can have both in/out for the filter in each tank...
maybe im just confused..but doesnt that sound easier?
maybe im just confused..but doesnt that sound easier?
Plainzwalker - without siphons between the tanks, that solution is one guaranteed to flood. Think about it - your source is the total volume of both tanks, your output is distributed between two tanks by valves. How do you guarantee the return from each tank will exactly match the input to that tank?. It also assumes perfect valve function across either two or four valves, no fluctuations from particulates in the lines or against the valve gates of any of the lines/valves.
sorry im not that knowlegable when it comes to those types of things.. i didnt think it would cause flooding..i just thought the amount of water coming out of both tanks would equal the amount being put back in if the length of tubes where the same..
once again..i apologize
im not that knowlegable when it comes to those types of things.. i didnt think it would cause flooding..i just thought the amount of water coming out of both tanks would equal the amount being put back in if the length of tubes where the same.. once again..i apologize
No one was criticizing you--just correcting the difference between paper logic and real world effects. It sounds like it would work your way, until you take into account the fact that even if you buy 2 pumps that are exactly the same size, set them up the same way on the same day, they won't perform exactly the same. Many of us have experimented with setups, finding new and hopefully better ways to have ever more fish tanks, so can share our experiences and prevent some of the mistakes we made.
