Top Off = waterchange

[nasher8860]

I currently have a 27 gallon w/ a 10 AGA sump. As of right now I am using about 1 gallon a Day to topoff.
My question is since I am replacing a good amount of freshwater everyday....will it mean less frequent big water changes ie.. 10gallon changes???? Or should I still do frequent 25% changes every 2 weeks??

 

[rmhuntley]

no, you still need to do water changes. Evap doesn't remove the harmfull chems. When the water evaps, they just become more concentrated. once you add your top-off water, they fall back to where they were before the evap.

 

[nasher8860]

Thought so....I knew it wasn't that easy.

 

[Llarian]

In addition to that, DI water topoff doesn't replenish any trace elements that're used by the livestock from the original salt mix.

-Dylan