How often to do water changes?

[kaylae123 0]

I've been doing 75% water changes weekly and just had a discussion with the guy at the pet store who said that is horrible for my fish. He recommended only 25% change monthly. Just curious what you guys do.

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[fantailfan1 26,742]

25% monthly is not nearly enough. How much and how often depends on your stocking level (tank size, number of fish and their size, etc).

Did he give a reason that 75% weekly is "horrible"? I'm guessing not and if you asked him why he'd say

[Chris1251 490]

Chri here.... ROFL!!! After a month and a half of daily WC.... I think that the guy at the pet store was pulling your leg.... Or is truly misinformed....

[alexloo11 64]

I do 20-25% daily WC during the summer/fall, and 30% in winter/spring depending on how warm the ground water is.

[AquaAurora 357]

There are a lot of horribly uneducated petstore employees , I've herd some very absurd things over the years (including that bettas are from the Arctic, and giving them a heater will kill them!.. They're actually a tropical fish originating from Asia that prefer 76-82F temps) don't trust anything petstore workers say, research on the web for more accurate info, but don't trust petstores sites for care info as they can be just as bad as the employees.

There are people who do 90% water changes daily! (many discus owners). 

If you don't have one already, you should get a liquid/dropper based test kit  test ammonia, nitrite, and nitrate BEFORE a water change and see what your levels are.  You want 0ppm ammonia and nitrite with a cycled tank.  If still cycling (anything other than 0ppm for these tests show up) use Seachem Prime to bind ammonia and nitrite so it doesn't hurt fish, but beneficial bacteria and plants can still consume it fine-note prime does not bind nitrates, keep up on water changes during cycle. And nitrates below 20ppm ideal, 40ppm being the max from what I've read.

I have 2 fancies in a 40g breeder with an insane amount of water sprite (aquatic plant) and lettuce, spinach, and cucumbers growing aquaponically (roots in water) so my nitrates are at 5-10ppm and I typically do 2 water changes a week 10gs each. If I had no plants I'd have to do a LOT more water changes to keep nitrates down where they are now.

Edited August 4, 2016 by AquaAurora

[kaylae123 0]

25% monthly is not nearly enough. How much and how often depends on your stocking level (tank size, number of fish and their size, etc).

Did he give a reason that 75% weekly is "horrible"? I'm guessing not and if you asked him why he'd say

He said I'm getting rid of all the good bacteria.

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[fantailfan1 26,742]

 

25% monthly is not nearly enough. How much and how often depends on your stocking level (tank size, number of fish and their size, etc).

Did he give a reason that 75% weekly is "horrible"? I'm guessing not and if you asked him why he'd say

He said I'm getting rid of all the good bacteria.

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The majority of your good bacteria live on/in your filter media.  Some live on the walls of your tank, decor, etc.  The amount free floating in your water column is like taking a drop of water out of an ocean--not enough to make any sort of impact . . .

[SweetMamaKaty 2,788]

The only reason I can think why large changes could be bad is if your tap and tank pH aren't closely matched.  That's the only reason I try not to change more than 50% at once - but I think I could do it more than once a week if needed!

[Hidr 4,961]

For my goldfish I do large weekly water changes.  Same for my oscar.  For my planted tanks (without huge messy fish} I do less.  20% every other week and top off on the other week.  

[FishyMandy 6,277]

Yea so many stores will say to only do 25% monthly. They jut don't know what thy are talking about unfortunately.

 

I do 70-90% a week with my goldies

[Mikey 6,780]

This is why at the pet store I work at my manager and I have to fix so many issues. Whether it be a customer heard it from this place or maybe this place (not mentioning any names) or even from my bosses in my own store! () we (my manager and I) are always fixing people's tanks because of the crazy stuff they have been told. Sometimes when we tell them things they don't want to believe us because a more "reputable" (cough cough chain store) said it so it must be true when in reality it isn't.

Just earlier today I was dealing with a guy who didn't want to listen to what I had to say because he knew it all. Yup, those 30 dollars worth of fish you made me sell you are gonna go down the toilet literally because of your ignorance. The guy had a tank that had turtles and fish in it but removed the turtles and had no more fish and left it just running without anything for a year. He didn't bother testing the water or let alone change it. Not only that but if all fish to start a new cycle with he wanted to get angel fish. I flat out said no because of how sensitive they are. It's just some times you need to throw your hands up and when the person runs into an issue all you can do is fix it then when they are more willing to listen.

And on the other note to the actual pont of the thread, sorry! Haha I change weekly 90%. At my work the tropical system gets a pythoning weekly which I'm guessing we change roughly 75-100 gallons of it (320ish gallon system). In the goldfish system it gets a water change twice weekly. I do it on Sunday and my

Manager does the both systems on Wednesdays.

Edited August 5, 2016 by Mikey

[DawnMichele 6,045]

I do 50% water changes on my 125 and 55 every week.

[fingers 1,350]

30% very 2 weeks!! but my tanks are now all tropical..way less waste than goldfish!!!!

I put the hose in my pond for 30 minutes per week and let it overflow!!!!!

[mjfromga 1,784]

70-80% weekly on the cycled 55 gallon with 3 goldfish, 57 grams, 70ish grams, 26 grams... often broken up into two 30-40% changes. Nitrates stay around 10 like this.

For now I'm doing two 80% changes per week on a 30 gallon uncycled tub with two goldfish, 12 grams, 9 grams. See a bit of ammonia and nitrite at each test, yesterday saw FAINT nitrate.

10% change weekly on uncycled roughly 70 gallon porch pond with 3 goldfish 9 grams, 8 grams, 8 grams. Never seen anything at all show up on test.

Edited August 6, 2016 by mjfromga

[shakaho 6,312]

If you read our guidelines for healthy goldfish, you will see we recommend a minimum change of 50% a week.  I don't know of any reputable source of information on goldfish that recommends less.  I change 10% daily, which has much the same effect as 50% weekly.  

 

If you check around you will find similar recommendation for other species of large fish kept in aquariums.  Big fish produce big waste, and unless your aquarium holds hundreds of gallons,  goldfish rank as one of the larger aquarium fish.  Pet store employees give "generic" advice applicable to a tank of small tropicals, not to goldfish.