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DIY Auto Top-Off System

4240 Views 9 Replies 5 Participants Last post by  vidiots
Here is my idea for an auto top-off system. I didn't find one in this forum so I decided to do one of my own. I haven't actually made this system yet so I'm not sure it would even work at all.

Basically it just consists of a water reservoir (preferably an air tight container to reduce evaporation), a water pump, and two liquid level float switches wired into the pump's power cord.

Note: The tank's float switch must be mounted upside down or else it would always be in the "ON" position and you would have a big mess to mop up. The water reservoir switch should be mounted as pictured in the drawing and always be in the "ON" position. This switch is optional and is only there to prevent your water pump from running dry once all the water in the reservoir is gone. When the reservoir is empty, the switch would cut off the current and the pump won't turn on until you refill it. You should also make some sort of casing around the float switch in your tank to prevent it from going off by mistake. Snails and other inhabitants have been known to set them off and flooding the room. You might also want to add a check valve or something to prevent water from siphoning into the water reservoir. I'm not sure if they make some sort of check valve for liquid but a regular airline check valve might work if you use the right size tubbing from your pump to the tank.



If you see any problems with my diagram and/or have any opinions or suggestions feel free to post your thoughts.

I personally don't want to try this myself because this is a 110v setup and I'm afraid of frying my fish. If anyone here knows how to make this a low voltage system please let me know.

Ps. I am not responsible if you attempt this DIY project and hurt yourself or your fish.
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Looking at your pic, it might be easier to use an overflow from your main tank to your reservoir and then just pump the water back up to the main tank. The water level in the main tank will stay constant while the water level in the sump fluctuates. Switches and valves complicate the function and increase your odds of something failing and flooding. There are a number of different designs for overflow systems that are pretty bullet proof when it comes to failures. Another addition is just to add a small hole in the line running from the pump to the main tank located just above the water level in your main take. This little hole will allow air in when the pump is shut off and prevent water from syphoning back thru the pump. This is much more reliable than a check valve.

On mine the small hole is positioned so that it is facing the tank wall. This prevents it from spraying water all over while the pump is on.

Not trying to say that all the neat electric tech isn't really cool, just less reliable than gravity controlled systems.
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Check out this site:

Aquahub Homepage

They sell relays that would allow you to make it a low voltage system. They have kits, but I thought they have stuff you don't really need. If you look around the site, there are a few helpful diagrams on different systems.

I bought some floats and relays from them. Built two systems, worked fine.

I guess my only question is about the switch in the topoff tank. Not sure I see the necessity of it. How will that tank be filled with water? Manually? Or some other type of automatic system? RO or freshwater? If it's not RO, why even have a tank, just use a solenoid valve on the freshwater line.
Thanks for sharing. I built a similar setup for water changes, only instead of the water reservoir and pump it is connected to the house water pipe and the float switch controls a solenoid.

Your version should work well, except I would extend it a bit to allow for easy water changes once you are at it.
Thanks for all your comments guys.

Looking at your pic, it might be easier to use an overflow from your main tank to your reservoir and then just pump the water back up to the main tank. The water level in the main tank will stay constant while the water level in the sump fluctuates. Switches and valves complicate the function and increase your odds of something failing and flooding. There are a number of different designs for overflow systems that are pretty bullet proof when it comes to failures. Another addition is just to add a small hole in the line running from the pump to the main tank located just above the water level in your main take. This little hole will allow air in when the pump is shut off and prevent water from syphoning back thru the pump. This is much more reliable than a check valve.

On mine the small hole is positioned so that it is facing the tank wall. This prevents it from spraying water all over while the pump is on.

Not trying to say that all the neat electric tech isn't really cool, just less reliable than gravity controlled systems.
Sounds interesting, I will look up overflows. The hole in the tube also seems better than a check valve.


Check out this site:

Aquahub Homepage

They sell relays that would allow you to make it a low voltage system. They have kits, but I thought they have stuff you don't really need. If you look around the site, there are a few helpful diagrams on different systems.

I bought some floats and relays from them. Built two systems, worked fine.

I guess my only question is about the switch in the topoff tank. Not sure I see the necessity of it. How will that tank be filled with water? Manually? Or some other type of automatic system? RO or freshwater? If it's not RO, why even have a tank, just use a solenoid valve on the freshwater line.
I planned to fill the reservoir manually and shut it off when ever I do a PWC. I would connect it to my home's freshwater line but I would have to run a hose from the kitchen to the living room. As for the float switch in the reservoir, it's just optional. If and when the water level in the reservoir goes below the float switch, the system won't turn on and therefor preventing your water pump from running dry.


Thanks for sharing. I built a similar setup for water changes, only instead of the water reservoir and pump it is connected to the house water pipe and the float switch controls a solenoid.

Your version should work well, except I would extend it a bit to allow for easy water changes once you are at it.
What do you mean by extend it a bit more? I would like to see how you wired the float switch to the solenoid.
Wow, that web site that Steve5520 gave is very good. I ordered on of the kits. seems like a good way to go.
Thanks.
JR
What do you mean by extend it a bit more?
What I mean is, now you have an auto top-off. This is pretty much the refill part. All you need now is a way to remove water from the tank. You could put a T inline with a canister filter, and either use a ball valve for draining manually, or find a solenoid/timer driven solution.

There are some good auto water change projects on this site, a search will give you a lot of inspiration.

I would like to see how you wired the float switch to the solenoid.
If you click on the "Cheap Water Change" link in my sig, you will see how I set it up and connected everything.
If you're doing the DIY and just buying the bare float switch, I forgot to mention that some plastic pipe and end caps are a way to mount them if you're concerned about snails and such.

The Aquahub "jars" look sort of bad to me (not functionally, just appearance), so I made mine like what this guy sells.

AutoTopoff.com
Wow, that web site that Steve5520 gave is very good. I ordered on of the kits. seems like a good way to go.
Thanks.
JR
Yeah I agree, both those sites where great.


If you're doing the DIY and just buying the bare float switch, I forgot to mention that some plastic pipe and end caps are a way to mount them if you're concerned about snails and such.

The Aquahub "jars" look sort of bad to me (not functionally, just appearance), so I made mine like what this guy sells.

AutoTopoff.com
I was actually going to make the cover similar to this.
DIY intake cage to keep fish from getting sucked in
I agree with what the others have said, if your gonna go to the trouble of tapping into the house water supply, might as well go the extra step and tap into the house drain too, so that you can complete the system.

After building my auto water changer, I am fully conviced it is the only way to go with larger tanks. With it I spend less time maintaining my 180g tank than I do maintaining a 10g tank.
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