So - has anyone out there successfuly designed and used a BALANCED contiunous water exchange system on a smaller tank?

I am interesting as well.

Was Eric ever working on something like that?

I have thought about trying something like this. Never gotten past the concept stage though, due to cost and space issues. I would be interested to see if anyone else has made this work.

Well, I have a prototype running - but it is not behaving the way I expected it to. I think I may have an air leak in the out-syphon.....

IT will successfully replace the water in the tank at a steady rate - in and out - by syphoning. That works well. But it is not capable of being "reactive" - responding to a stopped flow. I want a system that will self-regulate, so that I can never have the risk of an overflow.

I just wondered if anyone else had done it, and if so HOW.

I shall diddle with it for a few more days and try to take pictures.....

How do you treat new water? This is my main concern.

I found some online b4

http://www.monsterfishkeepers.com/forums/s...ead.php?t=27474

http://www.monsterfishkeepers.com/forums/s...ead.php?t=74749

http://www.monsterfishkeepers.com/forums/s...ead.php?t=75372

But those are for big system.

A reactive system. I would have two sensors placed in the tank towards the top, so each sensor should be centered where you want the water lvl. If sensor A goes too high, then the pump thats adding water to the tank turns off, or if its a siphon effect you have a valve that will shut allowing the water flow to continue later without priming the siphon.

If sensor B drops too low then same thing, but on the outflow tube/siphon. I am imagining using some sort of sensor like what gas tanks use to tell when to turn on the gas light. The sensor would have to be wired into either the power of the pumps, or into the valve fitted onto the hoses. Or you might find a wireless type, but you might get interference with the signal on that.

Big can be made "little".

I have well water and RO water - I use a combination of the two in a "recipe" I have developed, in combo with RO Right from Kent. These make up my fish ater. I do not have to be concerned with chlorine or tap water problems.

I do not, however, have it connected to the tap. I have a large bucket containing my mix water on a DIY stand higher than the tank, where the water is stored and syphoned from.....

I will look at the designs on those pages. Thanks!

Sensors and electrical equipment is easy to set up and make function. But it becomes useless and sets the tanks up for catastrophic failure in the event of power loss. I do not want that.

I wish to set it up with NO power needed - just using gravity and physics. It is possible. I just have to tweak it......

Maybe by adjusting the lvl (height) of your intake bucket so the water flow stops at a certain heighth?

The outtake flow can be regulated by only placing the tube into the aquarium at the minimum depth you would ever want the water to go to.

What about a float system like is used in the tank on a toilet?
Could even use toilet tank parts to build it.
Siphon water from a point high in the tank so that upon a failure of the system, tank level could only drop to the level of the siphon pickup.
When level dropsand the float drops, the fill valve would open.
When level was back up, float would shut off fill.
Siphoning off water would be continuous.
Filling would be on and off as needed.
Could set it up to only fluctuate level up and down ~3".
Could set up fill rate such that it is less than drain rate so tank could never over fill - but this could still fail if siphon was lost. It would be best to have an emergency overflow routed to a drain - but that would require a hole cut in the glass at the top of the tank.

Just throwing around some ideas.

Montman

A good way to regulate the outflow from the tank is with an overflow box hung on the back of the tank, as in this photo:

The large grey pipe on the left is the standpipe, or drain. The two transparent hoses on the right are siphoning out of the tank.

How this works is:
1) Water siphons out of the tank and into the box, so that the water level in the tank will try to equalize with the level in the box.
2) Water drains out of the box through the drain pipe, but the water level cannot drop any lower than the inlet of the drain pipe.

Thus, the water level in the tank can only drop as low as the top of the drain pipe, and can do so without breaking the siphon of water out of the tank. You can adjust the height of the drain pipe to suit your setup.

As for the new water going into the tank... I think a float valve is the only way to go. It would be safe to use an electric float sensor only if it operated a pump (not a valve), so that in case of power outage the pump shuts off (the only safe way of doing the electric-valve approach requires that the valve's default position is "closed"... or that one uses a UPS to power the sensor/switch). An in-line check valve from the pump will prevent back-siphoning. You can get a large water-supply-sized check valve from the hardware store in the PVC/plastic pipe section.

here's a link to the diy overflow box: http://www.cichlid-forum.com/articles/diy_...ss_overflow.php
here's an overflow w/ a skimmer box: http://www.cichlid-forum.com/articles/diy_overflow.php

Here's the link to the picture above that doesn't show up.

Never mind. It doesn't work either. I'll have Thomas find it again and upload it to his Photobucket account when he gets home from work.

Oh, I uploaded it directly from the url in Photobucket and it worked.

This all works well. I wanted a system that took up as little space as possible. To address this, I invented a small "syphon regulator". It is working well in Betta version and will soon be placed into production.

Will you please post some pics of your creation? I'm very curious as to how the setup will work.