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VioletThePurple

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I already cleaned out my filter with tap water, but afterwards was told not to do that because it rids beneficial bacteria. But there's other items in the tank that can have good bacteria too right? Like the decor, plants, and gravel hasn't been messed with. What effect will this have on my tank? What do I do now? I hope this isn't enough to have to go through the Nitrogen cycle again.
 
I already cleaned out my filter with tap water, but afterwards was told not to do that because it rids beneficial bacteria. But there's other items in the tank that can have good bacteria too right? Like the decor, plants, and gravel hasn't been messed with. What effect will this have on my tank? What do I do now? I hope this isn't enough to have to go through the Nitrogen cycle again.
Most of the bacteria resides in the filter. When you rinse it will chlorinated water it will kill the bacteria. Monitor your parameters and do a large WC whenever you see ammonia or nitrite.

You may experience a mini cycle.
 
Most of the bacteria resides in the filter. When you rinse it will chlorinated water it will kill the bacteria. Monitor your parameters and do a large WC whenever you see ammonia or nitrite.

You may experience a mini cycle.
If I used tap water with conditioner instead, would that have been safe?
 
If I used tap water with conditioner instead, would that have been safe?
Also, if you have a pre-filter, you rarely need to clean the main sponge as the pre-filter grabs most of the gunk and the bacteria in the main filter stays undisturbed.
 
It depends. First, what is in your tap water, chlorine or chloramine? Second, do you have live plants?

You are correct that the filter is not the source of the majority of bacteria, the substrate is, which is why a substrate of sand or gravel (not too large a grain) is so important. If the tank is not overstocked, you can throw the filter away and all would be well, so obviously cleaning it makes no difference. There are some caveats to this...tanks stocked properly, mature established tanks (not just set up a week or month ago), and live plants all help here.

Chlorine is not going to kill all the bacteria unless it is very high (the chlorine in the tap water); nitrifying bacteria is not so susceptible as is commonly assumed. The exposure time may also factor in. I have washed filter media in tap water which has chlorine (no chloramine) for 30+ years and never had issues. I do have live plants, that makes a big difference.

Chloramine is stronger than chlorine, and might be an issue...but again the stocking, plants, and maturity of the tank still prevent problems.
 
Chloramine is stronger than chlorine, and might be an issue...but again the stocking, plants, and maturity of the tank still prevent problems.

Key words in red, above

In a "freshly" cycled tank, the majority of the BB (beneficial bacteria) will reside in the filter, and filter media...it's best to rinse these in old tank water, not chlorinated (chloramine) tap water

In a well-established tank, the BB will reside more prolifically in the substrate, and on deco, plants, etc

IMO, that distinction is important to observe
 
And for the record, I'll never rinse my filter media in tap water...for me, that's more effort than filling a clean bowl with a bit of old tank water right next to the tank, and letting the media sit in it during WCs/filter cleanings, than carrying the media to the tap
 
It depends. First, what is in your tap water, chlorine or chloramine? Second, do you have live plants?

You are correct that the filter is not the source of the majority of bacteria, the substrate is, which is why a substrate of sand or gravel (not too large a grain) is so important. If the tank is not overstocked, you can throw the filter away and all would be well, so obviously cleaning it makes no difference. There are some caveats to this...tanks stocked properly, mature established tanks (not just set up a week or month ago), and live plants all help here.

Chlorine is not going to kill all the bacteria unless it is very high (the chlorine in the tap water); nitrifying bacteria is not so susceptible as is commonly assumed. The exposure time may also factor in. I have washed filter media in tap water which has chlorine (no chloramine) for 30+ years and never had issues. I do have live plants, that makes a big difference.

Chloramine is stronger than chlorine, and might be an issue...but again the stocking, plants, and maturity of the tank still prevent problems.
Idk what my tap water has, but I do have live plants. According to a fish tank stocking calculator, it's not overstocked, and the tank is like two years old. So maybe these factors will make it okay.
 
And for the record, I'll never rinse my filter media in tap water...for me, that's more effort than filling a clean bowl with a bit of old tank water right next to the tank, and letting the media sit in it during WCs/filter cleanings, than carrying the media to the tap
Either way you have to take the filter out, and for me the bathroom is right next to the room with the fish tank.
 
Idk what my tap water has, but I do have live plants. According to a fish tank stocking calculator, it's not overstocked, and the tank is like two years old. So maybe these factors will make it okay.

I would check with your water authority, prob on their website, and see what they add, this is important. But given the rest of this post, you are not going to have any issues rinsing filter media under the tap, no matter what they add.
 
While any residual chlorine or chloramine in your tap water can present a danger to the fish, in an established tank rinsing the filter media in tap with either will not kill the bacteria.

Firstly, when there is ammonia around chlormaine doesn't kill the bacteria, it basically puts them to sleep and a bit of ammonia turns them back on. Chlorine is less effective as well. But both need to be present for longer than they will in the filter media.

Next, the amount of chlorine in the media after you rinse it and put it back into the filter is pretty small. As soon as water is running through it any small amount of chlorine would be so diluted as not to matter. And if you are adding dechlor to the tank or there is some residual still there. The chlorine/chloramine would be neutralized almost instantly in the tiny amount it is present.

I knew a major breeder and then importer in Chicago who rarely used dechlor. I would put changing water into holding containers an let it outgas. Chlorine leaves faster than chloramine. And he always rinsed his media in tap.

The bacteria are a lot hardier than most think.

Lee, W.H., Wahman, D.G., Bishop, P.L. and Pressman, J.G., 2011. Free chlorine and monochloramine application to nitrifying biofilm: comparison of biofilm penetration, activity, and viability. Environmental science & technology, 45(4), pp.1412-1419.

Abstract​

Biofilm in drinking water systems is undesirable. Free chlorine and monochloramine are commonly used as secondary drinking water disinfectants, but monochloramine is perceived to penetrate biofilm better than free chlorine. However, this hypothesis remains unconfirmed by direct biofilm monochloramine measurement. This study compared free chlorine and monochloramine biofilm penetration into an undefined mixed-culture nitrifying biofilm by use of microelectrodes and assessed the subsequent effect on biofilm activity and viability by use of dissolved oxygen (DO) microelectrodes and confocal laser scanning microscopy (CLSM) with LIVE/DEAD BacLight. For equivalent chlorine concentrations, monochloramine initially penetrated biofilm 170 times faster than free chlorine, and even after subsequent application to a monochloramine penetrated biofilm, free chlorine penetration was limited. DO profiles paralleled monochloramine profiles, providing evidence that either the biofilm was inactivated with monochloramine’s penetration or its persistence reduced available substrate (free ammonia). While this research clearly demonstrated monochloramine’s greater penetration, this penetration did not necessarily translate to immediate viability loss. Even though free chlorine’s penetration was limited compared to that of monochloramine, it more effectively (on a cell membrane integrity basis) inactivated microorganisms near the biofilm surface. Limited free chlorine penetration has implications when converting to free chlorine in full-scale chloraminated systems in response to nitrification episodes.

But if one feels safer not using untreated tap water, then use tank water during a water change. Put some in a bucket and rinse the media in it. No fuss, no muss and no tap :)
 
While any residual chlorine or chloramine in your tap water can present a danger to the fish, in an established tank rinsing the filter media in tap with either will not kill the bacteria.

Firstly, when there is ammonia around chlormaine doesn't kill the bacteria, it basically puts them to sleep and a bit of ammonia turns them back on. Chlorine is less effective as well. But both need to be present for longer than they will in the filter media.

Next, the amount of chlorine in the media after you rinse it and put it back into the filter is pretty small. As soon as water is running through it any small amount of chlorine would be so diluted as not to matter. And if you are adding dechlor to the tank or there is some residual still there. The chlorine/chloramine would be neutralized almost instantly in the tiny amount it is present.

I knew a major breeder and then importer in Chicago who rarely used dechlor. I would put changing water into holding containers an let it outgas. Chlorine leaves faster than chloramine. And he always rinsed his media in tap.

The bacteria are a lot hardier than most think.

Lee, W.H., Wahman, D.G., Bishop, P.L. and Pressman, J.G., 2011. Free chlorine and monochloramine application to nitrifying biofilm: comparison of biofilm penetration, activity, and viability. Environmental science & technology, 45(4), pp.1412-1419.



But if one feels safer not using untreated tap water, then use tank water during a water change. Put some in a bucket and rinse the media in it. No fuss, no muss and no tap :)
I did treat the tank with dechlorinator. Hopefully you're right and the beneficial bacteria is unharmed.
 
No need to hope. I am right. I have been at this for too long not to know the chemistry and biology involved. The bacteria can live through a bunch of things that will decimate fish. Bacteria do not eat, they do not breath they do not die if there is no ammonia or nitrite etc. they go dormant. The biofilm protects them from a lot of things.
 

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