How much water changing is too much?

[Laser]

I like to do a 20 percent water change about every 3 days. I was wondering if that was too much. Should I knock it back to 20 percent a week? I don't want to stress out the fish or vac the gravel too much.

 

[Lonewolfblue]

You can never do too much. I do 50% weekly on my planted tanks, and on my heavy bioload non-planted, 50% weekly, sometimes twice a week. The fish love PWC's, at least mine do.

 

[toddnbecka]

Changing 20% every 3 days is fine, I usually do 30-40% every week, sometimes 10-14 days, if I have too much else to do. It isn't necessary to vac the gravel that often though.

 

[Voodoo Chilli]

Probably isn't going to hurt, but out of curiousity- what size tank and what's in it?

 

[Laser]

i've got a 5 gallon, and a 20 gallon... I'd have more if I had the space hehe.

the 20 gallon has 8 cardinal tetras, and 2 guppies, and 2 green cories.

the 5 gallon has 3 guppies and a panda cory.

 

[jrp1588]

I do 50% water changes weekly in my tanks, I'd do more if I had time. haha.

 

[fish_4_all]

50% weekly here too. And my plants and fish seem to love them.

 

[TomK2]

The only way water changes could be bad is if they cause big swings in parameters by doing them. It is hard to imagine frequent water changes causing a less stable tank, it usually results in a more stabe tank.

 

[BrianNY]

There is nothing better you can do for your fish and your nitrifying bacteria colony than to change water. As TomK2 says, as long as the parameters are close the tank will be healthier for it.

 

[Squirt0170]

I would like to add I did 2 huge water changes to get my Nitrites down.. probably 75% a couple hours apart and it put most of my fish in shock and killed 2 bala's.. I personally wouldn't recommend this OR do it again... I would say do change an amount of water Your fish are comfortable with but don't shock the crap out of them like I did...

 

[DepotFish]

I think that your fish went in shock, Squirt, because the ph changed so much with the water changes. As long as the water is dechlorinated and the ph and kh are the same then there should be no problem with even a 100% water change everyday. The only issue would be to make sure filter media and bacteria are not exposed to the air.

 

[Lonewolfblue]

I would like to add I did 2 huge water changes to get my Nitrites down.. probably 75% a couple hours apart and it put most of my fish in shock and killed 2 bala's.. I personally wouldn't recommend this OR do it again... I would say do change an amount of water Your fish are comfortable with but don't shock the crap out of them like I did...

I've done 80% PWC's back to back (not 2 hours apart) and never hurt any fish. They absolutely loved it.

 

[BillD]

I favor large water changes, and do no less than 50%, but I have left the water running, and come back a few hours later, to water flowing on the floor, and no loss of fish. Probably changed at least twice the tank volume.