Water Change Issue

[NOLANANO]

What's Up Fish Fam!

I have recently started to have issues just after water changes and I wanted to see if anyone with more experience than myself had any insight.

Keep in mind that all of my parameters were consistent throughout this whole ordeal, no swings or spikes in PH, Water Temp, Nitrates, Nitrites, or Ammonia.

So, let's start from the beginning: About 2 weeks ago I did a 20% water change and immediately something seemed off in the tank, but it wasn't anything alarming right away. By that night, every fish in my tank was at the surface gasping hard for air.  I went to the disease board and @Colu asked a bunch of diagnostic questions, one of which was whether or not my water company did any maintenance recently. I then remembered that they did shut off my water a few nights before to do maintenance and testing. He mentioned that sometimes they increase the chlorine content in the water supply after maintenance to flush the system. Believing that my water supply is tainted, I just added more water conditioner to the tank and hoped for the best.

Cut to the next morning and while none of the fish look great, they are still alive. Even though I think it's a long shot because the water in my tap is clearly poison, I decide that I have no other alternatives, so I go ahead and do a 60% water change and use double the conditioner dose. After this water change, I notice that the fish are looking a little better. They are still breathing hard, but they are back at their normal swimming depths and not at the surface.  At this point @Colu and I rule out disease and are sure that it's an issue with the water. He says to do another water change and says I should get an airstone because its beneficial in general and it definitely couldn't hurt my current situation. I go get the air pump and the airstone, return home and do a 40% water change with double conditioner just like before and I set up the air stone. By that night, all my fish were back to normal and I was dancing in my living room because not 12 hours earlier I was sure they were goners.

Fast forward to 2 days ago.  It had been 2 weeks of healthy fish and it was time for another water change. I did about a 30% water change (with double conditioner) and by the next morning every fish was at the surface gasping for air.  Following the gameplan from before, I did a second water change around 50% and again the fish looked better but not great. A couple hours later they were at the surface again so I did ANOTHER 50 % water change. At this point I am defeated, annoyed, and confused.  Then my wife who can sense my frustration (and who also never even glances at my tank btw) says "you had bubbles last time."  Annoyed I replied with a sharp "WHAT?!" Because no way she spotted something that my big bad fish keeping brain missed.  I read blogs and watch Youtube while she can't even pick a neon tetra out of a lineup, what are the odds?  She calmy replies "last time you almost killed your fish you had bubbles."  EUREKA THE BUBBLES! I removed the airstone about 2 days after the last water change issue because it was too loud. I grabbed the airstone, put it in the tank, and plugged in the air pump.  Now my fish are doing wonderful again. 

The lesson I learned is that sometimes I can get to hyper focused on something and miss the answer that's slapping me in the face. The fact that my lovely wife only saw the big picture and not the details allowed her to see the missing piece.  So this woman who couldn't care less about my fish but DOES care about her dopey fish keeping husband saved my tank but I digress.

Which leads to my questions:

1) Is it an oxygen issue?

If it is an oxygen issue, why did I never have this problem before? And why wouldn't the water be oxygenated during the water change? I would think there would be enough surface agitation during the water change to properly oxygenate the water. And why were my fish fine for 10 days without the airstone if it is oxygen? I just find it hard to believe that this is the problem but its also clear that the airstone is the solution.

2) Is it a chlorine problem like I previously thought?

The Issue I have with it being chlorine is that I am using a lot of dechlorniator as I am double dosing both NovAqua and AmQuel which both detoxify chlorine.  I did read somewhere, however, that chlorine wants to be in a gaseous state so maybe the added surface agitation of the airstone allows the chlorine to dissipate quicker?

3) Is it something else I am not thinking of? Or possibly a combination of the two?

If anyone has any insight, I would truly appreciate it. I am super happy to have found what looks to be the solution but its driving me crazy that I don't really know the cause.

TL:DR: All my started fish breath heavy and staying at the surface after my last 2 water changes and they were saved by an airstone. What is the cause?

Edited December 15, 2022 by NOLANANO

[Guppysnail]

I’m sorry about your issues.
It really could be anything using a city water source. At one point they treated for some thing and I lost a nice amount of Snails a few years ago. Then they sent out a newsletter afterwards saying whatever issue it was, they were having they treated. It’s fine.
about two months ago when I was at one of the Fish Club meetings, one of the guys he’s been keeping Fish for like 50 years lost several. tanks of Fish.  His son in law works for the water company so he asked his son-in-law. They said that they had to flush the lines with large amounts of potassium. Our water has high magnesium and they interact poorly together. During that time I did a large water change on my big tank and stopped because my whole tank clouded almost instantly so I knew something was going on with the water, so I was fortunate not to lose anything. They also raise chlorine levels drastically at random. 
All that being said, I ALWAYS double up on conditioner.  I also always keep lots of extra air running in the tanks. Sadly that does not always cover everything they dump in our water but it helps a lot to cover bases  

 

[Biotope Biologist]

I am sorry to hear that. Unfortunately city water is not regulated nationwide like it is in other countries. This leads some cities to use chemicals that are not good for fish, and arguably not good for human consumption either.
 

I am not sure what the solution here is either. Perhaps buying a pool master test kit and using it before you use city water? Or depending on where you live there are aquifers with free water you can fill up at. Some even purchase a RODI unit and recombine necessary chemicals later.

Edited December 15, 2022 by Biotope Biologist

[MrWestCoast]

Maybe I missed this info, but when are you treating your water? Are you treating while filling the tank or do you treat after filling the tank? Any chance your city started treating water with Chloramines?

[Mmiller2001]

Sounds like high CO2 in the tap water. Fill a storage bin, and let it sit 24 hours before water change. Drop an air stone in it and triple dose dechlorinator while it sits.

[Katherine]

I seem to remember dechlorinators using up a lot of oxygen. Somebody correct me if I'm wrong about that. But it seems like a combo of extra chlorine and the extra dechlorinator using up the available oxygen, which would be why the air stone helps.

[Stephan1973]

I’m wondering if your water treatment plant is using sulphite to reduce oxygen in water to reduce bacteria growth. Sulphite is used as an oxygen scavenger. As an engineer we use it in eliminating oxygen in boiler water but I have heard of it used in RO system servicing. May want to ask the water company if they are using sulphite. 

[flyingcow]

On 12/15/2022 at 1:54 PM, Stephan1973 said:

I’m wondering if your water treatment plant is using sulphite to reduce oxygen in water to reduce bacteria growth. Sulphite is used as an oxygen scavenger. As an engineer we use it in eliminating oxygen in boiler water but I have heard of it used in RO system servicing. May want to ask the water company if they are using sulphite. 

I'm pretty sure they can't use sulfites in potable water. I used it for BFW, but we weren't allowed to put it in ingredient water for food process. I might be wrong. 

On 12/15/2022 at 12:48 PM, Mmiller2001 said:

Sounds like high CO2 in the tap water. Fill a storage bin, and let it sit 24 hours before water change. Drop an air stone in it and triple dose dechlorinator while it sits.

I'm gonna second this one. Have you tested your tap water? I'd check chlorine and total ammonia (if they use chloramines, both should show up). 

[NOLANANO]

On 12/15/2022 at 11:47 AM, MrWestCoast said:

Maybe I missed this info, but when are you treating your water? Are you treating while filling the tank or do you treat after filling the tank? Any chance your city started treating water with Chloramines?

Well I usually add the conditioner as I start to fill up but the last water change yesterday I waited until it was full and put the dechlorinator in as I turned off the faucet. As for chloromines, I believe they do use it because the tap shows small amounts of ammonia.

Thanks for all the replies. My conclusion prior to this thread is that there is some sort of gas exchange issue and the airstone clears it up. I will test the tap water's PH and test my tanks PH and see if it is different.  I also do think there are chloromines because the tap water has always shown small amounts of ammonia but this dates back to before my issues. I am also going to retest that and see if its more ammonia than I remember from before.

[Stephan1973]

How big is the tank and how big is your filter? Is there adequate surface movement? The surface water movement is what creates the air exchange. The air stone may be providing the additional surface movement for air exchange.  If you have floating plants covering most of the surface this can reduce air exchange. 

[NOLANANO]

75G and it has a Sun Sun cannister filter that is rated for a 90G. It has a spray bar that creates surface movement and there are no floaters.  I'm going to leave the airstone in at this point and hopeully my issues will be a thing of the past.

[Flumpweesel]

On 12/15/2022 at 6:06 PM, Katherine said:

I seem to remember dechlorinators using up a lot of oxygen. Somebody correct me if I'm wrong about that. But it seems like a combo of extra chlorine and the extra dechlorinator using up the available oxygen, which would be why the air stone helps.

This was my thought when reading, dechlorinator use 02 in the water to bind and remove the chlorine, if it has a lot to work with it can deplete your tank.

You could try prepping your water change water the night before and leave an airstone in overnight to restore the water.

But personally I'd get used to noise of having it in the tank permanently because all they do is make things better, you might be able to reduce the noise by slowing it down it reducing the bubble size