how low do you let your tanks get, before water change or top off???

[Magnum Man]

I have been trying not to do top offs anymore, but even as quick as I can do water changes with my pump out, pump in system, it can be hard to always fit it in, with as busy as life is... when I "built in" my tanks 30 years ago, the wood wall that over laps the front of the tanks, is one inch below the standard plastic frame... I really dislike seeing that air gap, at the top of the tank, you get, with low water levels, so if I see air, I try harder to do the water change, so about as low as I go, is around 2 inches below the tops of the tanks...

however, a lower water level isn't necessarily bad, other than telling me it's past time for a water change... I'm sure the oxygen level in the water is much higher, when the hang on tank filters become small waterfalls... the Hillstream fish like cool, highly oxygenated water, so I don't feel too guilty...

I've tried doing tanks with low water levels, but keeping that glass clean, and not water spotted, has always been a challenge, and seeing that air gap bothers me enough, I just haven't been able to do one of those tanks, long term...

 

[seangee]

I'm not a fan of gaps either, but with the current warm weather I have dropped all my tanks by an inch. I suspect they will stay that way until late autumn.

 

[sharkweek178]

I have lids on all my tanks. That goes a long way. Plus most of my tanks are in an air conditioned room. The one tank I don't is my betta tank. I'm not concerned about the tank getting too warm because he's a betta. He has a higher temperature tolerance than most. And his water has yet to go past that. But his tank never gets too low. I think because it's so humid. And I do regular water changes.

 

[gwand]

There are two main causes of tank water loss: evaporation and/or absorption by plants. When water evaporates the solute remain behind, and become more concentrated in the smaller volume of water. These solutes include the nitrogen waste products. When water is taken up by plant roots, many solutes go along for the ride. So you don’t have the same concentration phenomena. I top off my tanks that do not have many plants.