Are Water Changes Killing My Fish?

[Spencer Heaton]

Hi Everyone,

I am not new to fish keeping but I am new to planted aquariums and I have an issue that may be causing illness in my fish related to PH and Soil Substrate affecting water parameters.

I current have 13 tanks with 2 of them full soil bottoms and one with a lot of leaf litter and these 3 tanks seem to be the ones with issues. To note there is a little soil in the bottom of the leaf litter tank but mostly just sand/gravel mix.

Water Parameters are 0ppm for NH3/NH4, NO2 & NO3 and I have been checking regularly. I have had 4 fish die over the last 4 weeks (2 in one of the soil tanks (male apisto agazzi & otto cat), 1 in the other soil tank (male betta) and 1 in the leaf litter tank (female apisto agazzi) and all of them have exhibited the same symptoms. I have had no deaths in any of my other tanks during this time and actually until this last month I think my last fish death was a very old GBR about 6 months prior.

All of these deaths came about 3-4 days after a water change. I usually do about 40-50% once a week and I use tap water in all my tanks.

The PH for most of my tanks (when testing) has been around 7.4-7.6 which is identical to my tap water. Now before anyway says that Apisto's need softer water I know but the other Apistos in those tanks are all fine and most of them I have had for over 5 months (added the odd male or female here and there to balance out aggression). All fish were from a local breeder (except the Betta & Otto as I do not know where they were from) but all were being kept in tap water and been at the store for well over a month).

The only new fish in this equation I believe is the male Agazzi as I only had him for 2 weeks and when I got him I notices a cauliflower like growth near his head so I was treating that tank with the med trio.

The 2 soil only tanks have been up and running for about a year and the leaf litter tank was re-scaped about 6 months ago.

The symptoms all 4 fish showed was a lack of appetite, no energy (just sat on the bottom or under a leaf), labored breathing, and eventually died. No other fish exhibited any of these symptoms in the tank both before or since this includes glow light tetras, pencil fish, Bristlenose plecos, other Ottos, both Chinese and Siamese Algae eaters, rummy nose tetras, etc.

Ok - so here is my question.

I know that soil and leaf litter can affect (lower) hardness (tap water TDS is around 300) and PH so I am wondering if a water change of 50% could have killed these fish if the PH of the New water was 0.2 or 0.4 higher than the water in the tank that was being affected by the PH lowering properties of the soil and leaf litter? Also hardness may have been slightly higher in the new water.

Unfortunately I did not specifically do a PH or TDS test prior to these water changes as all the fish were looking fine and by habit I do not do PH or TDS in my usually test regime unless there are issues (i.e. I will be doing these next week).

Please let me know your thoughts on this or if you need any further information on the above.

thanks,

Spencer

 

 

[AndreaW]

It's impossible to go back and redo something we haven't done -- that being said, if you suspect a fluctuation in pH could have been the issue I would continue to test the pH of those tanks to see what happens in the future. Keep a log and see if the pH fluctuates between water changes, and when you do your next water change, do a smaller one and continue to monitor what happens to the pH.

An unstable pH does affect fish and they will show it in their gills and they will appear to have difficulty breathing. I have had one fish exhibit symptoms of a problem when all others seemed just fine. ie: a whole school of Cories was acting fine and happy, but one would lay on his back gulping air at the top of the tank and then lay sideways. I tested the water and had less than .25ppm Ammonia. As soon as I did a water change and add Prime, he was fine and happy. I think some fish, like people, are more sensitive than others.

[Spencer Heaton]

Thanks AndreaW - yes that was the plan for sure!!!

Just curious if anyone is aware of any specific illness that exhibits these exact symptoms if they are not water PH/Hardness related since it is only happening in soil or leaf litter tanks

thanks,

Spencer

[jwcarlson]

What's your water's pH straight out of the tap vs in a cup (or some other container) left to age for a day?  With an air stone if you can.

[anewbie]

If you use the same water at the same time for both the tanks with and without soil it is unlikely the water unless the soil tanks have leached and changed the tank chemistry. Another problem might be that you are disturbing the soil substrates and 'bad' bacteria is being released. I had this specific problem with a tank (it didn't have soil but it had a very fine substrate; i was able to reproduce the problem in another tank using the same substrate so i stopped using it and the problem went away). 

 

Another thing is that if you do water changes weekly it could very well be unrelated to the water change itself.... esp if it is happening a few days after the water change as you stated. I think you said 4 days after the water change - something like ph shock would be more immediate.

[Spencer Heaton]

On 3/2/2022 at 3:43 PM, jwcarlson said:

What's your water's pH straight out of the tap vs in a cup (or some other container) left to age for a day?  With an air stone if you can.

Hi JWCarlson - its 7.4-7.6 right out of the tap - after sitting in a bucket for a ~24 hours (no air-stone) it appears to be the same 7.4-7.6 color of the test is exactly the same its just the interpretation of the chart vs. color 

Edited March 2, 2022 by Spencer Heaton

[Spencer Heaton]

On 3/2/2022 at 4:16 PM, anewbie said:

If you use the same water at the same time for both the tanks with and without soil it is unlikely the water unless the soil tanks have leached and changed the tank chemistry. Another problem might be that you are disturbing the soil substrates and 'bad' bacteria is being released. I had this specific problem with a tank (it didn't have soil but it had a very fine substrate; i was able to reproduce the problem in another tank using the same substrate so i stopped using it and the problem went away). 

 

Another thing is that if you do water changes weekly it could very well be unrelated to the water change itself.... esp if it is happening a few days after the water change as you stated. I think you said 4 days after the water change - something like ph shock would be more immediate.

Hi anewbie - that is the theory I am working on - not so much that my tap water is bad but the fact that the soil and leaf litter has changed the PH enough that a 20 - 50 percent water change has a such different PH and GH that it would cause shock.

To clarify when I say 4 days later that is time of death - the symptoms are noticed a day or so afterwards.

Also, tank size may be an issue in one of the tanks 8.6Gal planted (ADA 60-F) and standard 10gal planted but the leaf litter tank is a 25 gallon cube so 5 gallon water change for it really is only 20% the other 2 I do a approx 2-4 gallons each week.

the substrate disturbance is an interesting thought but would that only affect 1 fish?

[Spencer Heaton]

Ok - quick update - completed PH testing today prior to water change and there is definitely a .2 to .4 PH difference (depending on color difference interpretation of the API test kit) for the full soil planted tank so I only did 25% WC versus usual 50%.

Thoughts?

Would .2 to .4 PH difference be enough to stress/shock a betta or apistos?

[anewbie]

On 3/7/2022 at 11:40 AM, Spencer Heaton said:

Ok - quick update - completed PH testing today prior to water change and there is definitely a .2 to .4 PH difference (depending on color difference interpretation of the API test kit) for the full soil planted tank so I only did 25% WC versus usual 50%.

Thoughts?

Would .2 to .4 PH difference be enough to stress/shock a betta or apistos?

I doubt .2 would shock the fish.

[HH Morant]

Some deaths which are associated with water changes are due to occasional super-chlorination of tap water by municipalities. Although the usual chlorine content may be 1 ppm or less, under EPA rules the city water department can increase that to 4 ppm.

Water changes during the super-chlorination period can kill fish if a 4 X dose of de-chlorinator is not used.

See the aquariumscience.org article entitled "Chlorine and Chloramine."

I don't know if that is what happened in your case, but I doubt that a pH difference of the magnitude described would be fatal to fish. If the deaths were indeed caused by the water change, a few fish were apparently more susceptible than others, regardless of what attribute of the new water killed them.

[Spencer Heaton]

On 3/7/2022 at 2:37 PM, HH Morant said:

Some deaths which are associated with water changes are due to occasional super-chlorination of tap water by municipalities. Although the usual chlorine content may be 1 ppm or less, under EPA rules the city water department can increase that to 4 ppm.

Water changes during the super-chlorination period can kill fish if a 4 X dose of de-chlorinator is not used.

See the aquariumscience.org article entitled "Chlorine and Chloramine."

I don't know if that is what happened in your case, but I doubt that a pH difference of the magnitude described would be fatal to fish. If the deaths were indeed caused by the water change, a few fish were apparently more susceptible than others, regardless of what attribute of the new water killed them.

Hi HH Morant - I always use Prime and actually de-chlorinate directly to the new water prior to adding it to the tank (still using buckets and water bottles). Because it is a liquid and I use small buckets/bottles it is always overdosed (Prime) because I cannot measure amounts that small. Thus, I would think if the water was 'super chlorinated' it would still manage that given the overdose.

I know that the chemical reaction of de-chlorination does produce small amounts of Ammonia so in theory this could cause more Ammonia than usual if it is super chlorinated even with Prime usage after 24hrs if not managed by bacteria in the tank.

Our Tap water does come from Lake Ontario so there could be something to the need to over-chlorinate if needed due to lake water origin

On 3/7/2022 at 2:31 PM, anewbie said:

I doubt .2 would shock the fish.

Hi anewbie - that was what I was thinking too!!!

[Wrencher_Scott]

Maybe next time check for ammonia after the wc. A small amount won't hurt anything for sure though. Esp not fast.

I think I would test for chlorine just because. I test it after the dechlore and before I add to the tank because it's a FAST killer of fish at even small amounts. 

Say it was even a minute amount, it would upset the fish, dissipate, then they could recover but you know their gills will be damaged. 😞   I have read that in chorine fish will dart around like the are trying to get away from it but I have never witnessed it thank God.              

Ya, there is no way that pH did anything.

I would suspect bacteria too in the media like leaves, ect. I don't know anything about leaf litter tanks but I cringe just thinking about it and harboring bad bacteria in it. Don't the leaves rot?? Maybe the water change stirs it up ??

Have you ever tested your tap for nitrites and nitrates? It would have to be a lot I guess but wouldn't hurt.

Anyway, just my two cents, I wish you luck with it. 

On 3/7/2022 at 9:40 AM, Spencer Heaton said:

Ok - quick update - completed PH testing today prior to water change and there is definitely a .2 to .4 PH difference (depending on color difference interpretation of the API test kit) for the full soil planted tank so I only did 25% WC versus usual 50%.

Thoughts?

Would .2 to .4 PH difference be enough to stress/shock a betta or apistos?

No way.

Edited March 7, 2022 by Wrencher_Scott