Question Water Change Schedule

nikm128

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So I've always made myself live by the at least 25% a week rule. I usually do more like 35% but I just started wondering how often I actually need to do a water change. The way I see it is, the tank consistently has 0 ammonia and nitrites with ~20 nitrates even if I go two weeks (only vaccuming the gravel) without a change. So my question to you guys is, how much do I really need to change that often if it doesn't impact the water parameters at all after 2 weeks?
 

goldface

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Some people go a month or more with no problems. I've done it. Lots of people have. I used to go by a weekly water change schedule, too, but then I realized old water, although still good parameter-wise, is still old. So now I try to do it as often as I can. Thus, there is no consistency in my schedule anymore. For me, it's like going to the gym and working out, or running a few miles: some weeks I do it almost every day, and other weeks I feel like not doing anything at all. And that's acceptable in my view--if parameters are stable. In short, I do it when I have time and whenever I feel like it. Like today, for instance, is the second day of me doing a 90 percent water change in one of my tanks, although I didn't need to. And tomorrow I'm planning on doing another one, for the same tank, just because I can. I'm also certain that I can go out of town for 2 weeks or more and be perfectly unconcerned with the knowledge that the fishes will be fine.

On nano tanks of 5 gallon or less, the 25% per week change doesn't make sense to me. In a volume that size, a 50 percent or more should be done. It's more important to do more in a smaller tank. And hey, it takes a lot less time than it does a 20 gallon and larger tank so why not. It only takes less than 5 minutes to do a 90 percent water change in my 2.6g Fluval Spec III.
 

Betta'sAnonymous

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Yeah....I am kind of an opportunist as well with water changes. I know my bettas can go at least a couple weeks typically, but I make sure the 10 gallon gets at least 40-50% change once a week and the 5s twice a week (or more). The 10 I usually just do when I get the others, just easier that way. My wife usually changes the 20g's twice a week, because she likes crystal clear water and honestly, they might be a bit overstocked. Either way, our fish tend to stay healthy and fin rot free!
 
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nikm128

nikm128

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So basically, I should still do water changes whenever I can, but it's ok to just not feel like it at some point, and I have no reason to freak out (other than a friend forgetting to feed the fish) if I end up being away for a few weeks.
 

Betta'sAnonymous

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I also have to admit, we do not even have so much as a test strip in the house...so the frequent changes definitely serve their purpose.

nikm128 said:
So basically, I should still do water changes whenever I can, but it's ok to just not feel like it at some point, and I have no reason to freak out (other than a friend forgetting to feed the fish) if I end up being away for a few weeks.
Kind of...especially if well established. Would make sure to do a bigger change before leaving and when coming back though.
 
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nikm128

nikm128

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Oh definitely. scarface could you elaborate on "old water"? I think I get the general idea, but I don't fully understand.
 

goldface

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nikm128 said:
Oh definitely. scarface could you elaborate on "old water"? I think I get the general idea, but I don't fully understand.
Honestly, I don't have everything down scientifically, but I'll try to explain as coherently as I can as well as keeping it short.
We keep fish in a small, confined space. There is only so much "recycling" we can accomplish through nitrifying and even denitrifying bacteria. Fishes are still pooing in the same water. Old excretions are still in that same water as well. And who knows what else? We certainly don't test for everything and every possibility. I can have both aerobic and anaerobic bacteria and therefore have 0 ammonia, 0 nitrites, and 0 nitrates, whenever I test my tank water. But I'm not 100 percent satisfied with that in terms of the water being 100% clean or recycled. There are likely other things going on in the water that we don't look for on a microscopic level. For instance, hormones that fish excrete. What I want is to try and add as much clean water as I can, as if the fish are not in the wild, but a secluded mountain lake with no pollution. Space may be limited, but I want to at least give as much clean, oxygenated water as I can give them, almost as if space is an illusion (although there is only so much water one can change). I have strong, expensive air filters in my apartment, but even I will leave the window wide open, from time to time.
 
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nikm128

nikm128

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Nicely said, I followed that perfectly. I didn't even think about it at that level but it makes total sense to do it that way.
 

goldface

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nikm128 said:
Nicely said, I followed that perfectly. I didn't even think about it at that level but it makes total sense to do it that way.
I'm not saying my way is correct, but just how I do things. I see it as, if I have some extra time, then might as well do a water change. Why wait until the end of the week? But I think a weekly water change is percectly fine. My original point was why do only 15 or 25%, if you can do 50% or more per week? There is no scientific basis behind the 25% water change rule. I think for most people, doing a lot more makes more sense. Lots of clean water, instead of adding only a quarter or less of it.
 
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nikm128

nikm128

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Oh, I didn't mean to act like I was just blindly rushing in to your way of thinking. I just think that's a good way to look at it.
 

david1978

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Its like everything else in this hobby. There's only one right way to do it. Lol. A water change schedule has so many variables that each tank is different. With my current set up I do roughly 25% monthly. I have had other set ups that needed 50% every other day to keep the water quality under control. So the right amount is. Drum roll. It depends.
 

goldface

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nikm128 said:
Oh, I didn't mean to act like I was just blindly rushing in to your way of thinking. I just think that's a good way to look at it.
Nah, I wasn't saying that at all. Though I did wonder--seeing all the threads about people doing large water changes causing minI cycles and fish deaths--if I should add a word of caution to cover my butt, in case someone takes my advice and something bad happens and then blame me for it.
 
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nikm128

nikm128

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scarface said:
Nah, I wasn't saying that at all. Though I did wonder--seeing all the threads about people doing large water changes causing minI cycles and fish deaths--if I should add a word of caution to cover my butt, in case someone takes my advice and something bad happens and then blame me for it.
I'm really not even sure how they cause that. Maybe a large water change and throwing away a used filter cartridge.

david1978 said:
Its like everything else in this hobby. There's only one right way to do it. Lol. A water change schedule has so many variables that each tank is different. With my current set up I do roughly 25% monthly. I have had other set ups that needed 50% every other day to keep the water quality under control. So the right amount is. Drum roll. It depends.
Couldn't agree more with that one
 

DrTre

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Because I overstock my tanks, if I go two weeks without a wc my nitrates start skyrocketing, so I usually do at least one a week, sometimes two if time prevails. I try to live by the “ounce of prevention is worth a pound of cure” method, that goes with everything..

I’m not sure what all other minerals get replenished with wc’s, but that’s another reason I change at least once weekly. Unless you’re stressing your fish by making tidal waves, and sloshing plants and fish around during water changes, or not using something like prime to condition new water, I don’t see any cons to doing it at least weekly. Bear in mind, I have all fake plants in my setup.

Edit: 25 to 30% wc’s weekly
 

jaysurf7

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Well some do water changes more then others,most know it should be done at least once near every 2 weeks,I've went sometimes near a month and had no problems,don't think that small time frame can't affect the fish so much to worry about . I try to do mine at least once a week or every other week if . imo I also think doing to many water changes like every other day can also affect the fish as when you do water changes it takes time to settle and that can also affect the fish ,maybe stress them.Some times you won't do as many as you think you should and other times you'll do more then you usually do,like trying to find the right balance ,also when you add new water your also adding minerals vital for the fishes compared to the old water so I try not to let go too long ,but at the same time I don't stress if it isn't done when I think I should have if that makes sense lol.
 

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