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Anyone tried this? (Overflow pipe)


SamH

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The "Z Flow" overflow system. Hopefully my pic is good enough:

Overflow.jpg

Seen this quite a few times on various sites and overseas forums, would like to know if anyone uses this system?

I have a bunch of pipes and connectors lying around, would be a great way to add a sump to my 2ft cube.

Thanks

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A few of problems off the bat,

if the water level in the tank drops below the intake level (which it will) it will suck in air and loose your syphon.

if you loose power you will also loose syphon causing a flood when the power comes back on.

the syphon can only be started if you have both ends of the overflow underwater (or otherwise blocked), depending on how you have it set and how much it flows this could be a problem. When the pump is off the display tank end will be out of the water, when the pump comes on you may only have a short window before the sump end is out of the water (assuming you are actually home when the syphon needs restarting). :lol:

Do a search on "weirs" it will do what you want it to, will be a lot safer, and use a lot less expensive plumbing bits.

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Living art's design will work, I have one on one of my tanks, restarts after power cuts.

Down side is it's a bit big and hard to get it quiet. I would drill my tank if I had the option, but it was imported and the retailer advised against it incase any part was safety glass.

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i believe the first one will cut off when tank level drops and not restart as suphew outlined but i believe the second should start back up again as it will hold enough water in tube for gravity to restart flow

i have used a straight syphon overflow for awhile now that works but is susceptible to micro bubble buildup

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I have a box full of what looks like 2cm pipes and connectors from a soccer goal kit. The pieces aren't as thick as PVC and aren't air tight but fit very well together. They won't be under much pressure and I'll silicone all the out of water joints anyways.

Perfectly level? :o

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as i understand it

return pipe, returns water back to the tank from sump via a pump

overflow pipe takes water from tank to sump

water returned to tank then usually flows ot ouf tank through an overflow box/weir via a hole in tank or a syphon setup as described if no hole available

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I might cut the pipes tomorrow then, but I'm not very good with being precise :-?

Now what to put in the sump :roll:

Might make it a jungle/mass plant growing centre using reverse photosynthesis to combat CO2 overdose at night.

What do you think? Any other ideas?

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The reason the setup in the first link you gave works is because it is setup like a weir box stopping the display tank end from being out of the water. The second link if you look half way down the page he added a check valve and link to a powerhead. This does the same job as your sucking on the starter, but relies on the check valve and air tube not being blocked, and the powerhead starting. IMO an accident waiting to happen.

Livingarts change will work sometimes, but relies on having the correct water levels and the amount of air in the rest of the pipe. The problem is the water level and amount of air in the pipe is likely to change depending on how long the syphon has been off. As the water inlet (in the display) gets further below the 'T' it becomes less sensitive to having the correct amount of water in the pipe (this is the same idea behind how the first link you gave works, basically using the whole tank as a weir).

Marine keepers have been using sumps for a very long time and tried lots of different options. You will only ever see two types, weirs and drilled tanks. Because these are the only ways to have 100% reliable self starting systems. Proper weir systems have the air hose and power head system as well, but this is to remove air build up from the top of the "U" not to restart the syphon.

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Would this work?

Sumpoverflowbox1.jpg

The idea is that there is a syphon either directly in the tank or from another box inside the tank that pulls water in this external box. The water then overflows from the first chamber to the second chamber where it then flows into the bulkhead which takes water down to the sump.

Sounds like a bit of a hassle though.

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overflow.jpg

This is what mine looks like

The light blue line is when everything is running,

The dark blue line is when there is a power cut or interuption to water flow that causes the tank's water level to fall below the inlet. As you can see there is still water in the bit that goes over the side of the tank. If the syphon is broken in this bit everything will not restart.

As you can see the inlet on mine is very long, thats for the greater water flow. I get about 2000L/hour, using 32mm pvc, with a tap closed 3/4. Fully open and it sucks more water than my punp can return and constantly makes a loud sucking sound.

If you look at the green arrow, that is where the outflow will suck to when power is off. From that you can see why your first diagram won't work. The "u" in the inlet is way above the t-joint illistrated in my diagram. Livingart's diagram has the t-join way higher to stop the syphon flow breaking

PS make sure the breather pipe extends higher than the tank's water level, cause I have a tap in the sump, if I turn the tap fully closed, water will flow up the breather up to the tank water level, trouble waiting to happen if you have a shorter breather.

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I'm not so much worried about the power going off as I am the whole thing leakign and not working. I need to by an alarm that alerts me when there's a power failure, where can I get or make one of these?

Cricketman: Would the pump not work against the flow of the water if it was on continuously?

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I'm not sure why you need to reinvent the wheel, drilling a tank is simple and safe, I have done it many times, even have my own drill set. The reason glass shops say it is hard is because if by chance they do break the glass they know they will have to replace it. Suddenly a $10 hole costs them $100 in glass and a 1 hours time fixing it. If you really don't want to have the tank drilled a proper weir is really the only answer.

The problem with all the systems discussed above is none of them will reliably self start, they might go into idle fine most of the time, but if the syphon stops (which sooner or later it will) they wont restart. All a low water alarm is going to do is, tell you your fish are dieing and your floor is getting wet, not much use if your two hours away from home. :o

If you look at the green arrow, that is where the outflow will suck to when power is off.

Not sure if you drawing is to scale, but it looks like 3/4 of you tank is going to drain if the power goes off?

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