This is a discussion on what should i be testing my water for? (freshwater) within the Freshwater Chat forums, part of the Aquarium Related Chat category; Originally Posted by Scherb Agreed gh is important, are water is way to soft to leave unchecked. as for checking ...
Self proclaimed "Buffer crusader!" "Anti cyanide crusader!"
Also, are people so concerned chlorine because it can kill the friendly bacteria or because it can actually kill your fish directly with the dose in our water?
If it is the former case, with 90% water change twice daily using water that has been sitting aerated overnight do I still need to be concerned with Chlorine?
Last edited by Fish rookie; 11-21-2012 at 07:51 PM.
Yes, chlorine can kill fish in the doses coming out of the tap. Metro Vancouver keeps 'free chlorine' above ~0.6 mg/L (Seymour source) or 1 mg/L (Capilano and Coquitlam sources); that's well over the LD50 (the dose at which 50% of animals die with acute exposure) for most fish. Note too that the amount of chlorine added needs to be increased when the water is unusually turbid, e.g. after a very heavy rainfall.
Personally, with that big a water change I wouldn't risk an overnight aeration, I'd hold the water for a full 24h or treat with a dechlorinator.
Map of Metro Vancouver Tap Water Source & Supply | watermatters
I am open to correction on that, though, if others have further information.
2011 report including measured values of free chlorine, copper, lead, nickel, etc. in the source water and after treatment, from Metro Vancouver:
Last edited by ibbica; 12-11-2012 at 09:49 PM.