spiff;3437340; said:People doing large WC's probably stage the water first in another container, bringing it to needed parameters before adding it to the main tank.
If you're doing large WC's with out this, then there is the risk of hurting everything in the tank, depending on how careful you are with matching dechlor and PH control in relation to the added water.
Plain tap water kills BB. So just adding tap water will set back your bio filtering a bit. This effect is lessened depending on how much tank water is left to dilute this effect, chems added, ect.
I do 50+% water changes quite commonly...
I add tap water & dechlorinator straight to the tank...
The above quote is making some assumptions and speculations that are very frequently not true... no offense...
Every water supplier uses their own mix of chemicals to "clean" their tap water. Eacfh of us has to learn what we can and cannot do safely. Just because your supplier uses large quantities of chlorine doesn't mean mine does... But at the same time just because I get away with something doesn't mean you can...
"plain tap water kills BB"... that is completely untrue... chlorine does, chlamorine does... but not all of us have so much in our tap water that it cannot easily be removed by dosing the tank with dechlor as we add water...
It drives me insane how much speculation and assuption is passed around here written as fact.