Help! Water change killed fish?? O2 problem? - The Planted Tank Forum
 6Likes
Reply
 
LinkBack Thread Tools Display Modes
post #1 of 32 (permalink) Old 12-14-2017, 03:15 PM Thread Starter
Algae Grower
 
ScottieB's Avatar
 
PTrader: (0/0%)
Join Date: Nov 2010
Location: West New York, NJ (Hudson County)
Posts: 42
Help! Water change killed fish?? O2 problem?

Hi all.

Let me start by saying I'm an intermediate planted tank keeper. I'm not new to nitrogen cycles or planted tanks, and my tank is well established - been running for several years. But I'm definitely not an expert - still learning and still making some dumb mistakes.

But this one has me a little confused, hoping you all can shed some light... pun?

Anyway, a few weeks ago I added a some new fish, and although I lost a couple in the first few days (UPS really screwed up!) things seem to have settled down.

It's a 26g bow front, planted with EcoComplete substrate. T5 lighting, fluval co2 (for now), EI dosing with dry ferts. I have about 20 cherry red and amano shrimp, some cardinals, some harlequins, 4 otos and assorted snails. I usually turn the co2 way down at night and on again in the morning. I have a very small amount of surface agitation for oxygen but not too much to preserve CO2.

So last night I did a 50% water change. I normally use both prime and aquasafe plus to dechlorinate (I switch, just use whatever I feel like on any given day). Perhaps THIS is where I screwed up, as I never really thought about the details until last night.

Usually what I do is use 2 5-gallon buckets. I add the prime to the bucket, then add the water, mix it around briefly and then add it to the tank. For whatever reason last night I kind of paniced and thought 'what if adding the prime to the bucket first uses it up too quickly and then the water that fills up the bucket after doesn't get treated?' So I added a touch more after the buckets were full, and then for good measure, added some aquasafe directly to the tank (I had never done this before... maybe this was my mistake??) after it was full again. I then fed the fish a small amount (they all ate) and then shut off the light and went to bed.

This morning, there were 3 dead shrimp (all very small ones) and 2 dead cardinals. The rest of the fish and shrimp were all at the surface of the tank. Shrimp were even trying to climb out. The otos and the snails all seemed fine. So it must have been oxygen, right? Any critters who could get air from the surface were fine.

I quickly did another 50% water change, adding only prime and only after the buckets were full. I did not add any directly to the tank. I was in a rush as I had to shower and leave for work, but after my shower I checked in on them and everything seemed back to normal. Fish were swimming around all over the tank, shrimp back to foraging near the bottom or on the plants.

So I'm pretty sure it was an o2 issue - but WHY? I didn't do anything differently than usual, my co2 was on VERY low all night (and the drop checker was somewhere between blue and green - again normal). There was no bacteria bloom, ammonia was 0 (I didn't have time to test the rest, but I really don't think I caused a mini-cycle), filters still running etc. Nothing (besides the dead and struggling fish) was out of the ordinary.

Can anyone help me figure out what happened?? Thanks!
ScottieB is offline  
Sponsored Links
Advertisement
 
post #2 of 32 (permalink) Old 12-14-2017, 03:32 PM
Planted Tank Guru
 
Nlewis's Avatar
 
PTrader: (3/100%)
Join Date: Dec 2015
Location: Northern Va
Posts: 2,405
Do you normally change your water at night? Do you know how much Co2 is in the water coming out of the tap? If thereís a fair amount of Co2 in your tap water and you changed the water close to lights out and the Co2 ran all night, thereís a good chance you gassed them.

Just a noob


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Nlewis is offline  
post #3 of 32 (permalink) Old 12-14-2017, 03:52 PM
Banned
 
PTrader: (0/0%)
Join Date: Jun 2017
Posts: 1,300
Quote:
Usually what I do is use 2 5-gallon buckets. I add the prime to the bucket, then add the water, mix it around briefly and then add it to the tank. For whatever reason last night I kind of paniced and thought 'what if adding the prime to the bucket first uses it up too quickly and then the water that fills up the bucket after doesn't get treated?' So I added a touch more after the buckets were full, and then for good measure, added some aquasafe directly to the tank (I had never done this before... maybe this was my mistake??)
Yes you made a mistake with the conditioner. People have killed fish and shrimp in the past by adding too much conditioner to the water. So I would not assume O2 was the problem. In most cases chlorine levels today are much lower than what they were in the past. So your initial normal dose was probably more than enough.
Surf is offline  
 
post #4 of 32 (permalink) Old 12-14-2017, 04:11 PM
Planted Tank Enthusiast
 
tamsin's Avatar
 
PTrader: (0/0%)
Join Date: Jan 2011
Location: UK
Posts: 921
Sorry for your loses. I would guess the issue was the prime. Overdosing it can deplete oxygen (it can lock up oxygen as well as ammonia) and you dosed extra and then added the aquasafe.

"Prime will not cause any damage to the fish if used long term. You can use it as often as necessary. Keep in mind however, that Prime is a reducing agent and if severely overdosed or combined with other reducing agents has the potential to reduce the oxygen in the tank. As long as there are ammonia, nitrite, and nitrate to bind with, then there should be no issues to worry about."

Using Prime to protect overstocked tank - Seachem Support Forums

Clean tank with not much ammonia etc. to bind with, minimised oxygen levels already and then overdosing the declorinator added up to not enough oxygen.
tamsin is offline  
post #5 of 32 (permalink) Old 12-14-2017, 05:08 PM
Algae Grower
 
PTrader: (0/0%)
Join Date: Aug 2017
Posts: 37
Well, I think this is a combination of things.

1. Seachem Prime claims it can be safely overdosed up to 5x the regular dose BUT it also has the potential to reduce oxygen.
2. You have low surface agitation. This keeps the CO2 in but does not allow O2 in.
3. Your water change water probably has a fair amount of CO2 in it. With the extra conditioner, it further reduced the oxygen levels in your new water.
4. Your CO2 was running at night
5. Water changed at night.

When you did your water change, you introduced more CO2 than your fish were used to and locked up the O2 with Prime/Aquasafe. At night, the plants don't use CO2 and the main way it is removed is through surface agitation. And even though the CO2 was on low, it was still pumping even more CO2 into the tank.

Some people say to add an air pump to a tank when overdosing prime. I had to do this for my SW tank when doing chemical treatment.

Really sorry for your loses. I'm new to the planted world and did not think overdosing Prime could hurt. Always new things to learn.
saltybuddha is offline  
post #6 of 32 (permalink) Old 12-14-2017, 05:11 PM Thread Starter
Algae Grower
 
ScottieB's Avatar
 
PTrader: (0/0%)
Join Date: Nov 2010
Location: West New York, NJ (Hudson County)
Posts: 42
Hey all thanks for the replies. Once again in trying to be overly protective I actually caused more problems!

So - a few basic questions about chlorine and dechlorinators.

First, how long does it take for chlorine to do damage? It isn't instant right, like it would take time for it to move thru the tank and start killing things right? So in theory I should be able to add it whenever - either before I fill my bucket, after I fill my bucket, or even directly to the tank after putting tap water in right? I mean in theory - I still plan to do it with the buckets, and I realize I used WAY too much last night. Just want to understand how this all works.

So prime works fast, almost instantly, chlorine takes some time to do it's damage, and prime isn't all instantly used up - it can keep working for a while after application correct? Like say I add a treated bucket of water, then more tap water on top - the prime from the first bucket would keep working once it's in the tank, and treat the second bucket?

Thanks.
ScottieB is offline  
post #7 of 32 (permalink) Old 12-14-2017, 05:57 PM
Planted Tank Obsessed
 
JusticeBeaver's Avatar
 
PTrader: (0/0%)
Join Date: Oct 2017
Posts: 373
Quote:
Originally Posted by ScottieB View Post
Hey all thanks for the replies. Once again in trying to be overly protective I actually caused more problems!

So - a few basic questions about chlorine and dechlorinators.

First, how long does it take for chlorine to do damage? It isn't instant right, like it would take time for it to move thru the tank and start killing things right? So in theory I should be able to add it whenever - either before I fill my bucket, after I fill my bucket, or even directly to the tank after putting tap water in right? I mean in theory - I still plan to do it with the buckets, and I realize I used WAY too much last night. Just want to understand how this all works.

So prime works fast, almost instantly, chlorine takes some time to do it's damage, and prime isn't all instantly used up - it can keep working for a while after application correct? Like say I add a treated bucket of water, then more tap water on top - the prime from the first bucket would keep working once it's in the tank, and treat the second bucket?

Thanks.
Chlorine damages gills and cause problems breathing. You could add it right to your tank. Check your water reports since chloramines are a whole different story and can cause ammonia spikes if you don't treat it properly.
JusticeBeaver is offline  
post #8 of 32 (permalink) Old 12-14-2017, 06:11 PM Thread Starter
Algae Grower
 
ScottieB's Avatar
 
PTrader: (0/0%)
Join Date: Nov 2010
Location: West New York, NJ (Hudson County)
Posts: 42
Ok thanks.

Another dumb question then lol... how do I go about getting one of these water reports? Do I need to contact public works for my town or something? I've seen people talk about these here before and did some quick googling without any luck.
ScottieB is offline  
post #9 of 32 (permalink) Old 12-14-2017, 06:17 PM
Planted Tank Obsessed
 
JusticeBeaver's Avatar
 
PTrader: (0/0%)
Join Date: Oct 2017
Posts: 373
Quote:
Originally Posted by ScottieB View Post
Ok thanks.

Another dumb question then lol... how do I go about getting one of these water reports? Do I need to contact public works for my town or something? I've seen people talk about these here before and did some quick googling without any luck.
Whoever provides your water should give a report. Just look at your water bill and check that for a website where you can download or read the report.
JusticeBeaver is offline  
post #10 of 32 (permalink) Old 12-14-2017, 06:23 PM Thread Starter
Algae Grower
 
ScottieB's Avatar
 
PTrader: (0/0%)
Join Date: Nov 2010
Location: West New York, NJ (Hudson County)
Posts: 42
Ah - I'm a renter. I'll talk to my landlord. Thanks again!
ScottieB is offline  
post #11 of 32 (permalink) Old 12-14-2017, 06:42 PM
Planted Tank Guru
 
PlantedRich's Avatar
 
PTrader: (2/100%)
Join Date: Jul 2010
Location: United States
Posts: 12,048
I find fish death to often be a combo of small things just like most accidents we hear about. But without actual test results and once things are somewhat level we can only guess. I find chlorine to be a pretty slow process, more like dying from a sunburn only on their gills? The chlorine in tap water is much the same as chloramine except for two major things. Chlorine does gas off pretty quickly so we don't have to treat water with it in the tap. We can actually just wait and it gasses off. This is the way it used to be done. But chloramine is designed to stay in the water with the advantage being that much less of it is needed to maintain safe levels all the way to the end of the lines. If using chlorine, we may need to add the max allowed 10ppm at the plant to get the minimum allowed 3PPM at the far end but using chloramine we might add 5 PPM at the start and still get the needed/required 3 PPM at the end. It is safer as we use less and it lasts longer but that does complicate things for us so we use Prime, etc. But even if we overdose, it is almost always safe so there are probably other points involved when fish die quickly.
Ammonia kills much quicker than chlorine so that is where I often look. A sudden rush of ammonia can come about if we do some simple things like pouring the water in quick and stirring a bunch of the substrate. This can do two things, one is it can kill a portion of our bacteria that was living on the surface of the sub but it can also stir a bunch of gunk that was below into the water column where it becomes ammonia. Pouring in from buckets, this might be easy to do?
Was it also time to clean the filter and wipe down the walls or maybe move some plants? Doing any one of these will cost you some bacteria so if we do several things at one time , each will put us a bit closer to an ammonia spike. That spike can be a rolling factor that comes through strong enough to kill fish which may be weakened from pass exposure but be gone when we get around to testing.
Water temperature changes can also be a hazard as harmless ammonium can become hazardous ammonia at different temps.
So I would review what combo of things might have happened as the single point of overdosing is pretty uncommon for quickly killing fish.
I find one of more common causes of fish death is trying to do too much, too quickly and that combo can push fish that look fine over the edge to death.
But testing is about the only real way to get the answers.

For the water report, just find what company provides the water then it depends on what size how that info is passed small can just post it on a bulleting board while larger are required to do more to make it available. Many times a search for Consumer Confidence Report (CCR) and the name of the supplier will find it online. But then do keep in mind that it will only give high, low and average on many points so it does not tell you what your water has on any specific date.
PlantedRich is offline  
post #12 of 32 (permalink) Old 12-14-2017, 07:52 PM Thread Starter
Algae Grower
 
ScottieB's Avatar
 
PTrader: (0/0%)
Join Date: Nov 2010
Location: West New York, NJ (Hudson County)
Posts: 42
Thanks for that post - all definitely things to consider.

The things that make we really wonder though are that A - I've done this exact thing countless times with no problems, and B - the snails and otos were fine, shrimp and cardinals and rasboras at the surface trying to get air.

So I'm relatively certain it was a lack of O2, I'm just trying to pin down why. I could have been an ammonia spike, of course, but I didn't do anything to disturb the substrate or anything like that, and I didn't notice any sort of bacterial bloom or anything else. Besides, if it were ammonia wouldn't otos be affected more? Wouldn't everything in the tank be affected equally rather than critters who are able to get O2 from the surface being fine?

I really appreciate all the info. At the very least I hope I can learn from this!
ScottieB is offline  
post #13 of 32 (permalink) Old 12-14-2017, 07:57 PM
Planted Tank Guru
 
Nlewis's Avatar
 
PTrader: (3/100%)
Join Date: Dec 2015
Location: Northern Va
Posts: 2,405
Iím really curious about the levels of Co2 in your water source. Test the ph level right out of the tap and record that number. Fill a glass with water from the tap and test the ph of that 24 hours later. Compare the difference and this will show you some kind of level of Co2 thatís in your water source.

FYI, I regularly overdose Prime with no issues. Not saying thatís not the problem, just my experience.

Just a noob


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Nlewis is offline  
post #14 of 32 (permalink) Old 12-14-2017, 08:23 PM
Planted Tank Guru
 
PlantedRich's Avatar
 
PTrader: (2/100%)
Join Date: Jul 2010
Location: United States
Posts: 12,048
Sometimes the obvious is what confuses us on the small details. Not at all sure what has happened so not assigning any high value to this but just some general thoughts? One thing that may get confusing is the reason for fish to go to the surface. To get more O2 is likely but then the need for more may be a sign that something else is going on rather than a true lack of O2. Too much CO2 can make fish behave as if there was a lack of O2, even though it isn't that CO2 replaces O2. It can just be that as the gills operate, they get a higher percentage of CO2 and lesser of O2 so they behave the same. And then to throw a wrench into our thinking, some fish will act far different to the same situation. Some can tolerate low O2, high CO2 , etc. more than others. Some of that is genetic but then there are also times when condition changes the result.
Thinking of humans, we expect an 18 year old to be able to run better than a 50 but that changes if the 18 is a heavy smoker, has allergies or other conditions. So we find the same may confuse the issue like now. Some of the fish may have had unseen health issues, been more effected by some water parameter which we can't see or "something".
I have killed so many fish and sometimes I can put my finger on what happened but then there have been times when I never knew what happened. Kind of like predicting the weather, we think we have it figured out but it sure doesn't work at other times.
I'm afraid we still have a lot to learn. Good to wonder and try to do better but then I have to settle for less at times.
ScottieB and ScottieB like this.
PlantedRich is offline  
post #15 of 32 (permalink) Old 12-14-2017, 09:15 PM
Planted Tank Obsessed
 
PTrader: (0/0%)
Join Date: Jul 2017
Location: Sparks, Nevada
Posts: 341
Were the fish that were near the top visibly gasping? I might have missed it but how much did you actually end up dosing in total (what size is your tank as well)?

If you dosed a lot in excess it very well could have been depleted oxygen.
Highseq is offline  
Reply

Tags
None

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the The Planted Tank Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome