Something I've Always Wondered...

[matt_storey]

Something I have always wondered is, when you do a massive (50%+) water change, is there ever a chance you could "uncycle" your tank?

 

[markandhisfish]

you could knock back your filters bacteria if you forgot to dechlorinate , but so long as you dechlorinate you can doo 100% no problem at all

 

[matt_storey]

aaaaaaah, i always put a few drops in every bucket i pour in so i should be ok. its just something ive always wondered...

 

[markandhisfish]

you can do it either way . i used to do it like that , butr when i upgraded and a 50% w/c became 60 gallons of water i just refill with the hosepipe , and add dechlorinator straight into the tank . the only difference is you add enough dechlorinator to dose the tanks volume instead of for the amount of water changed. but just to be safe i turn off my filters do the water change then turn them back on again .

 

[Gilli]

You wont uncycle your tank even with bigger water changes than that as the bacteria live inside the filter, and in the substrate etc. No need to add some dechlolor to each bucket, just put the whole lot into the first refill bucket and carry on refilling - that way there is no danger that you lose count of how much dechlorinator you have put in!

 

[OldMan47]

Water changes will not affect the tank filter's bacterial colony unless you do not dechlorinate. If I have a tank where I do not like the chemistry, I will often do a 90% or bigger water change to place things back on track. The filter seems unaffected and the fish often look better after the change.
They don't care much for swimming around on a damp substrate for a few seconds though.