Does evaporation replacement have the same effect as a water change?

[SimplyVibing]

Kind of a noob question. This is mostly in regards to my freshwater tank— the room it’s in is hot and humid, and the tank is in direct sunlight. It loses a lot of water in the two weeks between water changes (probably 30-40%).

This tank also has an incredible amount of plants, snails, and shrimps. If I top it off with clean water, does that eliminate the need for a water change?

 

[Fishtheatre]

I would say not because the water that evaporated leaves behind whatever substances that were within it. For instance, if it was saltwater and the water evaporated, the salt from the evaporated water would still be there leaving the remaining water with a higher salt content. I imagine that applies to other substances as well. Always do water changes. Well, some people don’t and do well, but there’s a method to their madness as well.

 

[Peace River]

Kind of a noob question. This is mostly in regards to my freshwater tank— the room it’s in is hot and humid, and the tank is in direct sunlight. It loses a lot of water in the two weeks between water changes (probably 30-40%).

This tank also has an incredible amount of plants, snails, and shrimps. If I top it off with clean water, does that eliminate the need for a water change?

No, top offs don’t replace water changes. Evaporation only removes water and leaves minerals, wastes, other nutrients, and other things in the tank, whereas a water change removes all of those things from the tank.

 

[S2G]

No it probably makes it worse. When water evaps it leaves the bad stuff behind in higher concentration. If your topping with rodi it prob just levels back out but if you use tap it adds more bad stuff.

 

[SimplyVibing]

No it probably makes it worse. When water evaps it leaves the bad stuff behind in higher concentration. If your topping with rodi it prob just levels back out but if you use tap it adds more bad stuff.

I would say not because the water that evaporated leaves behind whatever substances that were within it. For instance, if it was saltwater and the water evaporated, the salt from the evaporated water would still be there leaving the remaining water with a higher salt content. I imagine that applies to other substances as well. Always do water changes. Well, some people don’t and do well, but there’s a method to their madness as well.

No, top offs don’t replace water changes. Evaporation only removes water and leaves minerals, wastes, other nutrients, and other things in the tank, whereas a water change removes all of those things from the tank.

Thanks guys!!

 

[Porpoise Hork]

The only way a ATO would work as a water change is if you had it setup as a continuous water change system where it is constantly adding clean s/w and the exact same amount is drained off via an overflow. It would have to be dialed in fairly close with a controller so it keeps up with evaporative loss so the salinity level stays stable. You would also need a both fresh and SW storage tanks connected to it as well as a plumbed in drain.

 

[LondonJon]

The only way a ATO would work as a water change is if you had it setup as a continuous water change system where it is constantly adding clean s/w and the exact same amount is drained off via an overflow. It would have to be dialed in fairly close with a controller so it keeps up with evaporative loss so the salinity level stays stable. You would also need a both fresh and SW storage tanks connected to it as well as a plumbed in drain.

That would not be an ATO.
With an automatic water change system, as you describe, you would still get evaporation and would still need an ATO.