ATO Fails ON... Does Sump or DT Overflow?

[Dinkins Aquatic Gardens Verified Sponsor]

So let's say I have my RODI system hooked up directly to my sumps return chamber, and let's say the float valve gets stuck on. What will overflow, the sump or the display tank?

 

[blaxsun]

If you have an emergency overflow, just the sump. If not, potentially both.

 

[WallyB]

Typically your Sump is below your tank, so sump will overflow and flood your floor if the water supply is endless, and your ATO has no smarts to turn off after a time limit.

So if you are directly hooked up to a Float Switch in your sump, that's not an Smart ATO, it will keep filling endlessly from your RO system.

Trust me those Float Switches do get stuck. Happened to me a few times.
In my case I use a Direct RO system hookup to a bucket. Bucket has the ATO float switch, so bucket is alway full.
I then have a Smart ATO that draws water from the Bucket. Tank is protected from a endless water supply.

 

[Gtinnel]

Your sump would overflow. Any fluctuates from a change in total volume effects the water level in the sump, the return chamber specifically (at least until it overflows into other chambers, and then overflows out of the sump).

If you have an emergency overflow, just the sump. If not, potentially both.

How can it be potentially both, without an emergency drain? There is no extra water going into the display tank than normal

 

[Spieg]

Yes, your sump will overflow and the salinity level in your tank will bottom out (unless you have a float switch in the sump that will turn of the return pump). IMO there is no smart system that can guarantee this won't happen. If a solenoid gets stuck open, there is no timer or computer that will fix that.

 

[SuncrestReef]

Your best bet is to utilize multiple layers of redundancy. I use the Neptune ATK which has 4 layers of safeguards to prevent overflows:

1. Low water level sensor, used to detect when to turn on and turn off the ATO.
2. High water level sensor. If the low sensor fails to turn it off, the high sensor turns it off and an alarm notification is sent.
3. A timer that doesn't let it run for more than X minutes. If both the low and high sensors fail to turn it off, and it runs longer than normal (a value you specify which is normally long enough to account for typical evaporation in your system and environment) then the ATO is turned off permanently until you manually intervene to turn it back on. You will receive another alarm notification of this abnormal situation.
4. A mechanical float valve to pinch the supply line closed. This is the last line of defense.

I have never had any ATO overflows with the ATK in the 3+ years I've been using it. See my tutorial on the Neptune ATK for more details:

Neptune Apex Programming Tutorials, Part 3: Automatic Top-Off Kit (ATK)

Part 3 of our series on learning how to program your Neptune Apex for automatic top-off in a saltwater aquarium.

www.reef2reef.com

You can also build this same type of multiple redundancies with other automation controllers and some DIY skills.

 

[Gtinnel]

Your best bet is to utilize multiple layers of redundancy. I use the Neptune ATK which has 4 layers of safeguards to prevent overflows:

1. Low water level sensor, used to detect when to turn on and turn off the ATO.
2. High water level sensor. If the low sensor fails to turn it off, the high sensor turns it off and an alarm notification is sent.
3. A timer that doesn't let it run for more than X minutes. If both the low and high sensors fail to turn it off, and it runs longer than normal (a value you specify which is normally long enough to account for typical evaporation in your system and environment) then the ATO is turned off permanently until you manually intervene to turn it back on. You will receive another alarm notification of this abnormal situation.
4. A mechanical float valve to pinch the supply line closed. This is the last line of defense.

I have never had any ATO overflows with the ATK in the 3+ years I've been using it. See my tutorial on the Neptune ATK for more details:

Neptune Apex Programming Tutorials, Part 3: Automatic Top-Off Kit (ATK)

Part 3 of our series on learning how to program your Neptune Apex for automatic top-off in a saltwater aquarium.

www.reef2reef.com

You can also build this same type of multiple redundancies with other automation controllers and some DIY skills.

Wouldn't it also be easy to add an extra layer by having it shut off the pump if the salinity took a substantial drop? I don't have the atk but I was going to use that as my final failsafe on my diy ato.

 

[blaxsun]

How can it be potentially both, without an emergency drain? There is no extra water going into the display tank than normal

Salinity change. But it's most likely moot since most have more than a single return.

 

[SuncrestReef]

Wouldn't it also be easy to add an extra layer by having it shut off the pump if the salinity took a substantial drop? I don't have the atk but I was going to use that as my final failsafe on my diy ato.

It depends on the salinity probe being used. The Apex probe is notorious for swings in readings due to bubbles, debris, or electrical interference. Also, if the water is so low that the salinity probe is no longer submerged, it will report low salinity, making the situation worse since the ATO wouldn't add water.

I never base any automation on the salinity probe reading, other than sending me alert notifications.

 

[Gtinnel]

It depends on the salinity probe being used. The Apex probe is notorious for swings in readings due to bubbles, debris, or electrical interference. Also, if the water is so low that the salinity probe is no longer submerged, it will report low salinity, making the situation worse since the ATO wouldn't add water.

I never base any automation on the salinity probe reading, other than sending me alert notifications.

I've had mixed feelings with my apex salinity probe. Currently it's working well for me so I'm trying not to touch it. If I start getting unrealistic swings I'm probably going to install the vca sps kit.
Also, my probe isn't in the return chamber, so in theory I should never have an issue where the water gets low enough to make the probe out of water.
Idk maybe I'll just use leak sensors as my final failsafe.

 

[Gtinnel]

Salinity change.

Sorry but I don't follow your logic. Definitely in the OPs hypothetical scenario the salinity of the tank will drop, if not caught, eventually to where the tank is almost completely fresh water. I don't see how the salinity of the water as any bearing on where the extra water goes.

 

[SuncrestReef]

I've had mixed feelings with my apex salinity probe. Currently it's working well for me so I'm trying not to touch it. If I start getting unrealistic swings I'm probably going to install the vca sps kit.
Also, my probe isn't in the return chamber, so in theory I should never have an issue where the water gets low enough to make the probe out of water.
Idk maybe I'll just use leak sensors as my final failsafe.

Leak sensors are never a bad idea, regardless of how many additional failsafes your already have. Just be sure to place the leak sensors on a layer of paper towel to avoid false-positive readings due to simple condensation or certain surface textures. A real leak will saturate the paper towel and set off the leak sensor.

 

[blaxsun]

Sorry but I don't follow your logic. Definitely in the OPs hypothetical scenario the salinity of the tank will drop, if not caught, eventually to where the tank is almost completely fresh water. I don't see how the salinity of the water as any bearing on where the extra water goes.

That's fine - it's probably not important in the grand scheme of things.

 

[Gtinnel]

Leak sensors are never a bad idea, regardless of how many additional failsafes your already have. Just be sure to place the leak sensors on a layer of paper towel to avoid false-positive readings due to simple condensation or certain surface textures. A real leak will saturate the paper towel and set off the leak sensor.

Thanks for the tip.

 

[WallyB]

Your sump would overflow. Any fluctuates from a change in total volume effects the water level in the sump, the return chamber specifically (at least until it overflows into other chambers, and then overflows out of the sump).


How can it be potentially both, without an emergency drain? There is no extra water going into the display tank than normal

I totally agree. Display tank won't flood even without an emergency drain. DT will run just like always.
Only if the DT single-drain get's plugged will DT flood without a 2nd emergency drain.

Sure the neverending RO water source will flood the sump and if it continues, the salinty will drop (which is bad) but only Sump will overfill/flood.

 

[WallyB]

Leak sensors are never a bad idea, regardless of how many additional failsafes your already have. Just be sure to place the leak sensors on a layer of paper towel to avoid false-positive readings due to simple condensation or certain surface textures. A real leak will saturate the paper towel and set off the leak sensor.

I totally agree. My leak sensors saved me a few times from various tank leaks, pipe crack, or even walking away while filling water to make up salt mix (then got distracted by a long phone call)

I also added one behind my dishwasher (in case hose cracks....which happened once and I only figured it out when water was dripping in basement), and one behind my washing machine (since if hose ever breaks, it could flood the house)

I've used these super cheap versions, that only trigger an audio alarm. Only works if you are at home and hear it.
A leak detector is useless if battery is dead, so some beep to let you know it battery-change-time.

Just last week I got a two pack of these DLINK Water Sensors from costco for $60 CDN.
https://ca.dlink.com/en/products/dch-s161-mydlink-wi-fi-water-sensor
The benefit is I'll get email alert (if not around) if a leak is sensed. Haven't tested them yet, and wonder how long a battery can last if it connects to Wifi. (Maybe just connects to wifi breifly, if there is a leak detected).

 

[Gtinnel]

I totally agree. My leak sensors saved me a few times from various tank leaks, pipe crack, or even walking away while filling water to make up salt mix.

I've used these super cheap versions, that only trigger an audio alarm. Only works if you are at home and hear it.
A leak detector is useless if battery is dead, so some beep to let you know it battery-change-time.

Just last week I got a two pack of these from costco for $60 CDN.
https://ca.dlink.com/en/products/dch-s161-mydlink-wi-fi-water-sensor
The benefit is I'll get email alert (if not around) if a leak is sensed.

I'm going to try using some incredibly cheap rain sensor boards that I got off Amazon hooked up as a switch. I saw some YouTuber (I don't remember who) say that they worked reasonably well. I'll probably start off just using them for a notification instead of controlling anything, until I test them enough to have some confidence in them.

 

[WallyB]

I'm going to try using some incredibly cheap rain sensor boards that I got off Amazon hooked up as a switch. I saw some YouTuber (I don't remember who) say that they worked reasonably well. I'll probably start off just using them for a notification instead of controlling anything, until I test them enough to have some confidence in them.

There is another option, if you have an Apex or Tank controller that can get Switch inputs.
No need for sensor board/ardiuno/raspPi or any power to run the sensor. No need to spend money on Apex's overprice ATK kit. .


For Apex you would need a Break out box, and it will give you 6 inputs. (So up to 6 water sensors, if you have spare inputs on the Break out box.
https://shop.neptunesystems.com/products/i-o-breakout-box

Just an example, but I got a better quality version of the above passive water sensors. (Forget the brand name).
No batteries needed. It's a passive sensor. When it get's wet it's like a Push Button Switch (switch closed). When dry (switch open).

I have it hooked up to Apex (via Breakout, not ATK), and have it placed on my Tank Stand, in a way that if tank overfloods (Return Drain plugs), and water gets to it. If the Apex picks up the Closed Switch (wet), it turns off my return pump, preventing a tank overfill flood. A 2nd one could be put on the floor to stop the return pump and avoid DT getting filled with Fresh water should sump overfill with Top up Water.

No you cannot use them in your tank for LOW SENSE, since the contact would corrode in salt water.

 

[Gtinnel]

There is another option, if you have an Apex or Tank controller that can get Switch inputs.
No need for sensor board or any power to run the sensor. No need to spend money on Apex's overprice ATK kit. (just need the breakout cable).


Just an example, but I got a better quality version of the above. (Forget the brand name).
No batteries needed. It's a passive sensor. When it get's wet it's like a Push Button Switch (switch closed). When dry (switch open).

I have it hooked up to Apex (via Breakout, not ATK), and have it placed on my Tank Stand, in a way that if tank overfloods (Return Drain plugs), and water gets to it. If the Apex picks up the Closed Switch (wet), it turns off my return pump, preventing a tank overfill flood. A 2nd one could be put on the floor to stop the return pump and avoid DT getting filled with Fresh water should sump overfill with Top up Water.

I'm going to try using something similar but even cheaper

The little circuit board isn't needed though. It functionally works the same as what you posted. Water makes a connection between 2 contacts completing the switch.

 

[WallyB]

I'm going to try using something similar but even cheaper

The little circuit board isn't needed though. It functionally works the same as what you posted. Water makes a connection between 2 contacts completing the switch.

https://www.aliexpress.com/item/328...&terminal_id=e89304082e874ec1aded0eb9f92746a0

THe one you show needs power (5 volts) to work (according to the specs). Seems to say that. Maybe I'm wrong.
Yes, if you give it 5 volts, it will act like a Digital Switch so would work with an Apex Break out box. (I'd test it before trusting it, when made in China and at that price)