Water Change Dangers

[labont865]

I havent been around this site for too long but I want to clarify something with any new users.

Water changes CAN be dangerous:

What you should do:

Do a 10-30% water change per week
OR
Do a 30-50% water change ever 3-4 weeks.

Vacuum your gravel regularly.

Clean you filter media regularly.

What NOT to do:

Never clean you filter media, Vacuum gravel, and do a water change at the same time. As this may remove all your good bacteria and cause your tank to restart its cycle which can lead to loss of fish.

Never do water changes more than 5-10% everyday UNLESS you are treating an illness in the tank, as once again you may remove too much of the good bacteria and cause your tank to restart its cycle.

Instead when changing your water choose to do one or the other clean your filter media or vacuum the gravel, But Never ever do all three at the same time.


I have been reading around this site that you can never do too many water changes and have probably been guilty of telling people this myself. However I have just made a Huge mistake in my tank which has lead to the loss of 6 ghost shrimp and my Hillstream Loach. I made the mistake of doing a water change, vacuuming my gravel and cleaning my filters sponge media. This lead to a huge spike in my Nitrates and ammonia, causing the death of my fish. I should have known better but I have never done anything like this before, and never had anything like this happen in my 15 years owning fish tanks and just assumed it wouldnt happen. But it is actually a common and easy mistake to make. So I read this book they had at my LFS and found an article on just this situation and figured I would make this post just to inform everybody of this.

Please comment on this as I would like to hear feedback. Or if maybe this is just a total fluke that it happened, which I doubt since this book made it pretty clear that it happens quite often

 

[StreetCypher]

I see no harm in doing large water changes as long as your water parameters temp are the relatively the same. I do 50%-60% each week along with a sand vac and rinsing of my media. Not once have i had a mini cycle.

Maybe something else coincidentaly happened at the same time as your water change that killed your fish?

 

[amerpatrt]

Whoa

:sad Thank you for the heads-up. I think people need to be made aware of this terrible SNAFU that you experienced. If you've been into aquariums for 15 years and this happened to you, then it is certainly something that needed to be 'put out there'. I appreciate it VERY much. Sounds like something I'd do. Now I'll be certain not to make that mistake. Thanx again,
Dawnundefined

 

[labont865]

Well I dont know what happened exsactly in my tank. All I know is that I did all three at the same time and literally the next morning I have 7 dead fish in my tank and my Nitrates and ammonia are through the roof. And this book Says that to be safe and guaruntee this wont happen to never do all three at the same time. As I mentioned I have never heard this before until today when I check this book. I mean the book is by far no Scientific fact book its just some guys personal guide to aquariums going by his experience, but I mean I usually dont do all three at the same time and one of the few times I do this happened. I usually do a water change and Vacuum the gravel but I dont usually do the filter on the same day. I do my filter during the week and I do my water changes on sundays, usually. I just know this guy said its a safer way to do it and so I figured I would let everybody know. I mean if you have a way that works by all means keep doing it I am just writing this more for the people who are new to Aquarium life.

 

[mayreee]

Never clean you filter media, Vacuum gravel, and do a water change at the same time. As this may remove all your good bacteria and cause your tank to restart its cycle which can lead to loss of fish.

How can you vacuum the gravel and not do a water change at the same time?

 

[Megatron]

Yeah I would agree that doing all 3 at once could be problematic but I disagree with what you are saying regarding water changes. I personally do anywhere from 3 -5 25% water changes weekly and have yet to experience any negative effects. I never lose fish and I have never had a mini cycle except when I have done all three (which I did not do again). I Only gravel-vac once or twice a week and do the filters every week or so ( not change them just squeeze out the sponge inside my tank). I dont really think you can do enough water changes (if done properly).

 

[RTR]

IMHO & IME, it is impossible to change too much water or too often - with the restrictions Spartan has already mentioned being observed. Many commercial breeders change 100-200% of the water in their breeder and fry tanks daily, seven days a week. Hobby tanks rarely require or even need that, but there is no downside there.

Filter cleaning is a separate issue from water changes, but neither should impact the other. If your filter cleaning is adversely affecting the nitrification bacteria in your filters, there is something wrong with that process itself, which can be addressed on the boards in an individual thread, as the technique does vary from one filter type to other filter types, and/or the water involved in the water change did not meet the disinfectant neutralization, temperature, other water parameter requirements, or perhaps both things. It is not uncommon for me to partial, filter clean, glass clean, etc. all at the same time - with no detectable after effects other than a cleaner, clearer tank with more energetic fish.

In short, I completely disagree with opening post in this thread. That can be poor tank practice IMHO.

Edit: BTW, I think I'm at about 50 years in the hobby now, and for the last 30+ have run a daily census of between a dozen and >40 tanks occupied, depending in part on the volumes of the tanks operating - from 10 to 180 gallons. Current census is about 2 dozen tanks.

 

[labont865]

Well that is your opinion and you are entitled to it but that doesnt mean that I am wrong.

I am also posting info I read in a book which I will get the name of for you guys tommorow. It is a fact that you need bacteria in your tank to keep ammonia and nitrates etc. in check and by doing all three at the same time the risk of removing too much of this bacteria is there. It opperates on the same principle of using filter media from an established tank to help bacteria grow faster in a new tank. Which mean that bacteria can be removed. If you do a thorough proper vacuming of your gravel there should be almost no debris or crud in that gravel meaning no source for the bacteria. which tends to also be the main source for a tank. And if you clean your filter thoroughly and properly there should be no more debris and crud in you filter either meaning no source for bacteria in there which means one less source of bacteria for your tank. When you do a water change you are removing water that already has the bacteria in it and replacing it with water that has none of the good bacteria in it. Therefor by doing all three it is very possible to eliminate too much of the bacteria for the tank to handle, leading to a mini-cycle in the tank.

So to try to say my post is wrong is total crap, However to say it is not that likely is fine. Because as I said I have had aquariums for 15 years and it has never happened before, BUT this doesnt mean it can`t happen. SO I figured I would post it in here just to make people aware of what happend and what I read that would help prevent it in the future.

 

[Slappy*McFish]

I have to agree with RTR on this. Performing all three at once should not affect your bacterial population anymore than doing them one at a time. A properly cleaned filter will retain the majority of it's nitrifying bacteria. Filter media that is cleaned under the tap in hot, chlorinated water will not. Vacuuming the gravel will not remove bacteria as the bacteria are firmly attached to the gravel, itself. It would require vigorous scrubbing and cleaning under hot tap water to begin killing the bacteria. And this statement: "Never do water changes more than 5-10% everyday UNLESS you are treating an illness in the tank, as once again you may remove too much of the good bacteria and cause your tank to restart its cycle." is false as nitrifying bacteria do not live free-floating in water. No amount of water changes(done properly) will remove/kill nitrifying bacteria. Untreated/chlorinated tap water added to the tank can, however.
I regularly perform weekly 50%+ water changes on my tanks. I very often will clean my filters and gravel vac at the same time. I've never disrupted my bacterial colonies by doing so.

 

[labont865]

Again I am just posting what I read in hopes to prevent the same thing from happening to somebody else.

I personally havent read that nitrifying bacteria isnt free-floating but that doesnt mean it isnt true. I could be mis-informed there.