Water Changes

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from what ive been told.... a 1/3 tank change is decent. even a half tank change is too much. it might shock, stress or set off the chemical balence too much at once. i may be wrong im no expert just my opinion and reserch. i personaly try to do a 1/3 tank change weekly
 
it's perfectly fine to do large water changes every week.


You will not be removing any nuitrients becuase any beneficial nuitrients are going to be present in both your tapwater and tank water.
 
I do about 50% a week...no ill affects, yet. I've read that replacing the tank water with new water replaces the nutrients and minerals in the water that the fish have used up...I haven't looked for anecdotal evidence of that though.
 
_Jessica_;4375151; said:
I do about 50% a week...no ill affects, yet. I've read that replacing the tank water with new water replaces the nutrients and minerals in the water that the fish have used up...I haven't looked for anecdotal evidence of that though.
this is one of the reasons we do water changes.


KH in your tank water tends be be used up by the acids produced by the decay of fish wastes the KH needs to be replaced before the pH can drop too much.



from what ive been told.... a 1/3 tank change is decent. even a half tank change is too much. it might shock, stress or set off the chemical balence too much at once. i may be wrong im no expert just my opinion and reserch. i personaly try to do a 1/3 tank change weekly

You have been told wrong. as long as the pH of your tank and your source water is the same (or close enough) your not going to shock your fish or cause a chemical imbalance.

i regularily do upwards of 75% water changes and my fish show even brighter colours the next few days after such a large change.


now you'd be correct if you've left your tank so long that the pH has dropped significantly from the pH of your tap water because then you need to do a series of smaller water changes to bring the pH back up to the tap water's pH. How long this would take depends on the carbonate hardness of your tank. Mine is medium hard and it takes over 2 weeks before i start to see a drop in pH (i do water changes every week though so unless i go on vacation i never see a pH drop)
 
Given a very stable tank you can do up to 75% and some people particularly Discus keepers often do this. IMO doing 30% 2x a week opposed to one big 60% WC is better. I do 25% 2x a week on a few of my tanks and have never had water quality issues or problems with my stock. Making sure your water temp is the same, ect ect.. are all important things to consider when doing changes of that volume.
 
MonsterMinis;4375168; said:
Given a very stable tank you can do up to 75% and some people particularly Discus keepers often do this. IMO doing 30% 2x a week opposed to one big 60% WC is better. I do 25% 2x a week on a few of my tanks and have never had water quality issues or problems with my stock. Making sure your water temp is the same, ect ect.. are all important things to consider when doing changes of that volume.
This is scientifically/mathematically incorrect
2 30% water changes do not amount to 1 60% change becuase during the seocnd water change you are technically changing part of the clean water you just added a few days earlier.
 
Thank you all i have heard both sides before and i like to big water changes because i can tell a difference in their color everyone brightens on up just didnt know if stress was the reason for the brighter colors like when a sail fish gets out of water

Thats my 44th post good number
 
On a properly stocked tank 50% a week is the minimun to change.

Over stocked tanks are better off with larger volume water changes.



You can change 80% a day without harming your fish..... 50% a week isn't going to hurt them at all.


Two changes of 25% a week does NOT change 50% of the water for the week. The first change is 25%, but the second change is changing water is already 25% new water so the second change is only changing about 19% giving you a weekly change of only 44%.
 
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