DEAD SILENT OVERFLOWS - SALT or FRESH

[Hookup]

http://www.beananimal.com/projects/silent-and-fail-safe-aquarium-overflow-system.aspx

This is not my idea, but it is a part of my quest for a silent running Display Tank...  This system will be going into my tank.  It seems to be the *best* system for safety and for noise period.

The system has 2 fail-safes to ensure that if you get a clog in a down-flowing pipe, you will not flood your system.  That is super cool...  And it's not overkill... because the two fail-safes are part of what makes the system silent, so you kind of need them anyhow....

The system is dead-silent.  There are only two ways to make water in a pipe silent.
1) have a low amount of water so it slips around the air in the pipe (hugs the walls with air in the middle)
2) have no air in the pipe (siphon)

This system uses both methods!  Therefore, immeidately think about 2 down-lines.. one that will be "low flow" and one that will be "no air" (a siphon).

The "Siphon Line" handles 99% of your water that needs to get down to the sump.  This is a no-air line, which is silent

The "Open Line" handles the 1% of water that is left over.. This is a low-flow line, which is silent.

Now over the two lines we have 100% of the water, dead silent!

You use a ball-valve on the "Siphon Line" so that you are NOT allowing 100% of the water down that line... the problem isn't 100% of water going down the siphon... the problem is having 110% capacity in the line for your specific flow... this means you get air into the line, and therefore do not have a full-siphon, and get the nasty gurgling noise....   By restricting the flow, you can get the flow down the Siphon Line to match your input flow, and create an airless siphon... no air = no noise...

But, getting it tuned to be exactly at 100% would be a nightmare... so we allow for the 1% extra water to flow down the secondary line, the open line... Which, because there is only a very low amout of flow going down the open line, it slides down the sides of the pipe without issue and is also silent.

Both of these two lines should exit "under-water" in your sump... this will help eliminiate any airbubbles in your sump... (and for us salties, that helps with salt creep, so it's win/win/win)...

There is a 3rd line which should be considered an OMG somethings crazy wrong and we have a backup down-line... and there is a built in air-line that allow the open-line to become a siphon in cases of an emergency (rising water) situation... as the waterline rises in your DT, it covers the airline, blocking it, and that turns your low-flow "open line" in to a siphon line... thus allowing a tremendous amount of water to go down that line...


This system works extremely well for HIGH FLOW SUMP designs... and for LOW FLOW SUMP DESIGNS...  however, it has been noted that for the high-flow systems, it can day several minutes for the system to self-adjust...

Also, as noted, you do NOT need ball valves on all three lines, just on the SIPHON ONE... cause you have to tune it to consume 99% of the water... the rest can be straight plumbed, or you could use True Unions for maintenance purposes...

Anyhow... I was so impressed with this system I had to share.