What is an auto top up? What does it do? Why do I need an auto top up? In this blog post we're going to take a look at this small but important part of maintaining a marine aquarium.
Over time your marine aquarium will inevitably lose water through evaporation. The amount of water that evaporates from aquarium to aquarium but is generally dictated by environmental factors such as whether your central heating system is on or not. The main issue is that when water from the aquarium evaporates the salt content of the water will increase because salt cannot evaporate. This is why we must replace the evaporated water with fresh RO water in order to restore not only the water level but the salinity. We could do this manually, which hobbyists with micro size aquariums do, or we could employ a system to automatically replenish the water, cue the Auto Top Up.
An Auto Top Up or ATO comprises of a water level sensor and a small pump with tubing. That's it. Simple. You place the water level sensor in the return chamber of the sump, the pump in to a container of RO water and route the tubing into the sump. When the water level drops, the sensor will be triggered which powers the pump which sends RO into the sump increasing the water level until the water sensor is no longer triggered. It's an incredibly simple piece of equipment but absolutely invaluable. Having an ATO takes the stress out of remembering to do the top up yourself and also helps to stabilise the salinity in the system.
There are simple ATOs available such as the TMC Auto Top Up Compact or you can opt for more monitoring capability by using a smart reef option such as the Reef Factory Level Keeper. Using something like the smart reef option means you could incorporate an auto water change function into your marine system through the functionality of programmable pumps. To get started though all you really need is a good reliable ATO. You'll thank me later.