Evaporation = Water change ???

[mansiz]

Hi, I would like to ask whether does evaporation same as water changes? I have a cooling fan which is blowing at the water and the evaporation rate is quite fast, I add about 1.5 Litre of fresh water everyday. So is this same as water changes? Do I still need to perform water changes every week? BTW does salt evaporate? Or just water will evaporate in SW?

 

[dralarms]

Salt does not evaporate. So when doing top offs you do not need to add salt. You need a test kit to answer the other question. If all your water paramators are good then yes, I guess you could use the 1.5 litre daily top off as a water change. What are your water paramaters?

 

[fishfreek]

I agree they are not equivilent. In adding water from evaporation your basicly pardon the pun. 'watering down' the concentration of salts, trace elements and other DOC's in the water. As water evaporates these levels get more concentrated in the remaning water. The change is fairly suttle since you should be doing daily or bi daily topoffs. The saltcreep you see is whats left behind when saltwater evaporates.

When you do a water change your physically tanking water out of the system and adding clean water back to the system. Your not only diluting whats in the system but your also removing some of the DOC's and impurites as well as adding back into the system some trace elements.

 

[mrrrkva]

Very Well said Fishfreek. You need to continue to do waterchanges, simply because the "bad stuff" is left behind when the water evaporates. When you topoff your water, just use fresh water (preferably RODI) If you dont use RODI water, you will be putting other impurities back into your tank