Spotlight on the Aquahub DIY Top-it-Off Kit | BRStv

randyBRS · Nov 29, 2017

Hey guys,

For those of you who like to save a bit of money and also enjoy DIY projects, today we're shining the light on the DIY ATO kit from Aquahub!

beaslbob · Nov 30, 2017

Interesting to this old heathkit builder. I especially liked the use of the 12 volt relay to isolate the 120v AC from the water. I have seen and heard of some that used the float switched to directly control the 120v ac pumps which is extremely dangerous. Like killing dangerous.

I do have two thoughts, question, concerns, and or general confusions. LOL

The first is siphon problems. Most would have the sump near for floor in the cabinet. With the ato pump/bucket at the same or above height wouldn't a siphon form through the pump and keep filling the sump with the pump off? Could there also be a reverse siphon through the pump with the pump off? In the latter case you just have the pump output above the sump water level to break the siphon. But with the first I can't see a way of preventing that unless the ato supply is below the sump level.

Secondly (and the testing I forgot to do in my first sump resulting in a flood months later. LOL) what about a drain failure (siphon break or blockage). The sump level goes down, display up, ato kicks in and continues running until the ato supply runs dry. With the real possibility of a display flood before running dry. Wouldn't it be a very good idea to add a display level float switch in series with the lower ato float switch so that both have to be below a certain level for the pump to kick in. So if the display goes up through a drain failure, the ato pump turns off.

Just a couple of random thoughts.

Hey I may even use these to keep my FW tank with no sump topped off. I get tired of carrying water to it. LOL

my .02

beaslbob · Dec 1, 2017

perhaps I don't know how to setup an ATO but just had a thought. If the water is pumped up to the higher container (usually the display), then the siphon problem goes away as long as the pumped top off line is above the water level to form a siphon break. Probably to the top of the drain would be a good choice with the top off can mix in the refugium/sump before entering the display.

randyBRS · Dec 1, 2017

beaslbob said:
Interesting to this old heathkit builder. I especially liked the use of the 12 volt relay to isolate the 120v AC from the water. I have seen and heard of some that used the float switched to directly control the 120v ac pumps which is extremely dangerous. Like killing dangerous.I do have two thoughts, question, concerns, and or general confusions. LOL
The first is siphon problems. Most would have the sump near for floor in the cabinet. With the ato pump/bucket at the same or above height wouldn't a siphon form through the pump and keep filling the sump with the pump off? Could there also be a reverse siphon through the pump with the pump off? In the latter case you just have the pump output above the sump water level to break the siphon. But with the first I can't see a way of preventing that unless the ato supply is below the sump level. Secondly (and the testing I forgot to do in my first sump resulting in a flood months later. LOL) what about a drain failure (siphon break or blockage). The sump level goes down, display up, ato kicks in and continues running until the ato supply runs dry. With the real possibility of a display flood before running dry. Wouldn't it be a very good idea to add a display level float switch in series with the lower ato float switch so that both have to be below a certain level for the pump to kick in. So if the display goes up through a drain failure, the ato pump turns off. Just a couple of random thoughts. Hey I may even use these to keep my FW tank with no sump topped off. I get tired of carrying water to it. LOL my .02

Yep, you pretty much have the concept of a siphon down! If the ATO reservoir water level is higher than your discharge hose line, you can run the risk of the water continuing to flow after the pump is turned off. Many reefers mitigate this by pumping the water to the top of the display instead, or even adding in some sort of siphon break fitting near the top of the ATO reservoir. The Neptune ATK has a good example of this as they utilize a 1/4" push-connect fitting with an angled hole drilled in it, to act as a siphon break when the pump stops.

I think the second scenario is most commonly mitigated through the use of secondary and emergency drains for the tank itself, rather than trying to rely on mechanical float switches in the display to act as a secondary control to the ATO. Inherently there seems to be more risk of potential failure that way, as those display tank floats will be highly susceptible to water fluctuations from turbulent flow or even the wandering critter like snails.

-Randy