Question: Water evaporation

[aaustin15]

So, i have fans on my tank and they make the water evaporate very quickly. when the water evaporates, can i just add new treated water to the tank or should i take out a little bit of old water too? i do weekly 20% water changes also, i just don't know how to go about filling it back up during the week.
thanks!

 

[FX1C]

Evaporation will leave a concentration of toxins behind as the only thing evaporating is water - a 20% change weekly is essential even in a well balanced, planted tank. (Think about how they obtain salt - they evaporate a huge body of shallow water to leave behind highly concentrated salt...)

I keep a few 20L buckets with dechlorinated water which I leave for a minimum of 2 days to age. It's not that difficult to syphon off the bottom of the tank with a gravel vac & then return the new aged water gently - I must be weird but I find carefully lugging buckets of water around quite therapeutic the fish certainly appreciate it



<3 >o_o< <3

 

[aaustin15]

so it is okay to just add treated water when it evaporates? (in addition to the 20% weekly water change)

 

[Jennewt]

"Ideally" water that evaporates should be replaced with distilled water. However, if you are doing those 20% water changes weekly without fail, this is probably not necessary. The amount of dissolved minerals will increase somewhat, but the water changes will keep it from getting dangerously high.

I have a rule for myself: I never "top off" a tank without first removing some water. But I will admit that I'm not always doing the weekly water changes, so this is usually the way I get some water change accomplished.

 

[aaustin15]

okay, awesome! thank you for your help!