The Office Manager Called, “Our 250 Gallon Aquarium Is Leaking!”
Running an aquarium maintenance company, you’ll be the one that gets the calls when shit happens. This is a cautionary post for anyone setting up an automatic-top-off (ATO) system!
- 3 billable, on-site hours + travel time + an emergency fee.
- New ATO system installation coming up.
- New biweekly maintenance service client. 2-2.5 billable hours.
I recently received a call from an office that called saying their aquarium was leaking. They’ve been using another aquarium service company but, I guess, weren’t happy with his response when they got ahold of him. Seems something he did that caused it and that conversation didn’t go so well. (I’ve since learned that this wasn’t the first time water has ended up on the floor under his care.)
The office manager typed, “leaking aquarium” into google and found our website (the ‘Aquarium Emergency Service page).
When I arrived, I found a pile of wet paper towels on the floor. Apparently, they had been mopping up the water as it slowly dripped. The sump had overflowed and slowly was spilling onto the floor. The “leak” actually had nothing directly to do with the aquarium leaking!
It was the float valve that controls the auto-top-off that had failed. It didn’t seal and just let water keep running into the sump 🙁
I’ve seen (and replaced) similar setups, numerous times over the years. There were two significant things wrong with this set-up…
1. The ATO relied on a cheap float valve to control a high-pressure water line. AND,
2. The ATO was plumbed directly into the building’s water supply.
DUMB!! That’s = a cheap, fallible valve holding back an unlimited amount of water from flooding an office building.
Thankfully, in this situation, it was early in the workday and as soon as the water started seeping out from under the aquarium stand, it got noticed. Imagine if that float valve failed on a Friday evening and ran all weekend?

It’s a saltwater fish-only tank and everything was fine in there. I’d guess about 30-40 gallons of freshwater entered the 250-300ish gallon system. Just enough to drop the salinity some. But, not enough to harm the fish.
If this had of happened to a reef tank, by the time I would have been able to get there, it would have likely been game over and the tank would be in the process of crashing.
As it ended up, there was a little bit of electoral damage (the power outlet was in the floor, under the tank) that needed an electrician to fix. But, that was about it.
Their invoice for this ended up being 3 hours on-site + travel time + an emergency/unscheduled appointment fee. And, we’ll be back to install a new ATO sensor+pump and a 20-gallon fw reservoir. And, we picked up a new commercial maintenance service client. 2-2.5 billable hours, biweekly.
The moral of the story… think long and hard about the consequences of plumbing an ATO system (or anything) directly into a never-ending water source if, something were to fail, that’s set up for a significant disaster.