Dead Platy? What Is Going On?

[Robbo89]

I currently have 3 platies (and about 7 week-old fry) in my 100L planted tank, last night I had 4.
 
After performing a waterchange and cleaning the external filters media in tank water (and adding new washed activated carbon) a few days ago my fish seemed to be staying at the top of the surface, gasping for air. Even the fry... I then woke up this morning to this....
 

 
No obvious signs of any illness, and none of the fry were affected... I assumed this was something to do with the oxygen content of the water so I took out some water in order to create a heavy splash from my spray bar, introducing oxygen into the water as well as putting in a second internal filter also with a spray bar. My water temp at time was around 23 C and parameters:
 
pH: 7.2
Ammonia: 0ppm
Nitrate: 0ppm
Nitrite: 0ppm
 
The tank was cycled using seachem stability by the way, I'm not too worried about the death, just that I have an order of 8 tetra arriving in a week... So I need to identify whatever issue I have an fix it, quickly  
 
Thanks in advance, Robbo.

 

[the_lock_man]

The chances are that there was a whole bunch of bacteria on the old carbon that you just took out and threw away - fish at the top gasping are suffering either from oxygen deprivation, ammonia poisoning or nitrite poisoning. Assuming your filter outlet was positioned correctly to ensure that the surface is rippling nicely, then the chances of it being a lack of oxygen in the water are slim.
 
You say you cycled the tank using Seachem Stability - how did you verify that the filter was cycled? And how long ago did that happen?

 

[Robbo89]

The chances are that there was a whole bunch of bacteria on the old carbon that you just took out and threw away - fish at the top gasping are suffering either from oxygen deprivation, ammonia poisoning or nitrite poisoning. Assuming your filter outlet was positioned correctly to ensure that the surface is rippling nicely, then the chances of it being a lack of oxygen in the water are slim.
 
You say you cycled the tank using Seachem Stability - how did you verify that the filter was cycled? And how long ago did that happen?

 
It's an external filter that also has bio balls, white filter wool and black filter wool which all would have had the bacteria as well,
I've tested the parameters as mentioned above though and no ammonia or nitrite was present? And if it was ammonia or nitrite wouldn't the fry have died first?
 
The filter was running for over a month without anything being added, then I dosed seachem stability as instructed for 7 days before adding any fish. All four adult platies were happy and healthy for 2 weeks until the waterchange...  

 

[Robbo89]

Just thinking, is there any negative to daily waterchanges? I'm on holidays now so I have more than enough time to perform a 50% change per day.... is it worth starting now and continuing as I add the fish this weekend?? Or are there any negative effects of changing that much water daily (ie stressed fish) 

 

[the_lock_man]

My issue is that your test results don't make sense. If you had a fully cycled filter, you would not get a 0ppm for nitrate. If you had a completely uncycled filter, you would not get a 0ppm for ammonia. There are two ways to get Triple Zero. 1) A brand new tank with only tapwater in it (and no nitrate in tap water) or 2) A fully cycled filter and a tank stuffed with more plants than you appear to have. Something in those test results isn't correct, in my experience, and the symptoms you describe and the methodology you used point to it being the ammonia, and possibly the nitrite, reading
 
Yes, you are right, the bioballs, and the sponges would usually have bacteria as well, but there is no way of knowing where in the filter the bacteria are. Each individual bacteria has a certain capacity for processing ammonia and nitrite, so removing a large proportion of that capacity will mean that ammonia is present in significant quantities. In a mature filter, the bacteria colonies will increase quickly to take up the slack. Bacteria that have only been given an ammonia source for 2 weeks, that may or may not have come from an "Instant Bacteria" product only 1 week previously, don't consitute a mature filter.
 
In my experience, a cycled filter takes 6 or so weeks, and a mature filter is no younger than 6 months.
 
There are no negatives about daily water changes, with the possible exception of your back muscles! In fact, in your instance, I would recommend it. However, I wouldn't recommend adding any fish, until you can verify that your filter is fully cycled with credible test results. For me, that means using a liquid drop test kit to see 0ppm ammonia, 0ppm nitrite and around 20-60ppm nitrate every day for a week.

 

[Robbo89]

Here's a photo of the full tank, but as you said there are not enough plants to keep the levels all at 0 ...

 
All I can think of is that when the waterchange was performed (a day before the death) about 60% of the water was removed, meaning the nitrite could have been removed this way causing the triple 0? Furthermore, I had to go to school minutes after I discovered the dead fish and so I only had enough time to remove the fish from the tank, meaning the test was actually done about 12 hours later. I will test again as soon as possible, and just for reference I have been using the API Master Kit. In my mind it keeps coming back to the fry, surely a week-old fry would not have a stronger resilience to ammonia or nitrite poisoning than an adult healthy fish?
 
So would you have recommended that I left the old carbon in WITH the new carbon for a few days maybe even a week or two? Just to ensure at least some of the bacteria had transfered?
 
Using seachem stability was not by any means my first choice to cycle the tank, it ended up being a last resort. None of my local stores were willing to give me any mature media to transfer and pure ammonia is not available in Australia due to it's prolific use in making bombs... The only reason I used it was that I was given it by a mate who breeds flowerhorns, and recently moved house. He told me he cycled 12 tanks with the stuff in 3 days, so I'm confident it's no gimmick chemical. No where near as good as pure ammonia cycling, but it SHOULD have done the job to a relatively average degree. 
 
The problem with the fish are that they have been ordered in, so my ability to hold off on them is pretty limited / probably very costly. No matter what is going on with the filter daily 50% water changes will maintain the fishes health, correct?

 

[eaglesaquarium]

Here's a photo of the full tank, but as you said there are not enough plants to keep the levels all at 0 ...

 
All I can think of is that when the waterchange was performed (a day before the death) about 60% of the water was removed, meaning the nitrite could have been removed this way causing the triple 0? Furthermore, I had to go to school minutes after I discovered the dead fish and so I only had enough time to remove the fish from the tank, meaning the test was actually done about 12 hours later. I will test again as soon as possible, and just for reference I have been using the API Master Kit. In my mind it keeps coming back to the fry, surely a week-old fry would not have a stronger resilience to ammonia or nitrite poisoning than an adult healthy fish?
 
So would you have recommended that I left the old carbon in WITH the new carbon for a few days maybe even a week or two? Just to ensure at least some of the bacteria had transfered?
 
Using seachem stability was not by any means my first choice to cycle the tank, it ended up being a last resort. None of my local stores were willing to give me any mature media to transfer and pure ammonia is not available in Australia due to it's prolific use in making bombs... The only reason I used it was that I was given it by a mate who breeds flowerhorns, and recently moved house. He told me he cycled 12 tanks with the stuff in 3 days, so I'm confident it's no gimmick chemical. No where near as good as pure ammonia cycling, but it SHOULD have done the job to a relatively average degree. 
 
The problem with the fish are that they have been ordered in, so my ability to hold off on them is pretty limited / probably very costly. No matter what is going on with the filter daily 50% water changes will maintain the fishes health, correct?

 
 
That might be the issue...  The API kit is tricky for nitrate.  Shake the stuff like crazy!!!  Follow the directions exactly, that might be why the nitrate is zero - it may well be a false reading.

 

[Robbo89]

So after talking to Wildbetta last night I did a few more things this morning, but im gonna keep this really short and simple.
did a 50% water change, but tested the water BEFORE i did so, results:
 

 

 
My interpretation:
 
pH: 7.2
Ammonia: 0.25
Nitrite: 0
Nitrate: 0 (the bottle was violently shaken and thrown)
 
I will continue to test the water daily and perform 50% water changes directly after, regardless of the parameters as the fish i have coming this weekend aren't exactly cheap. Will be striving for discus-breeding-water quality, so in the scenario that the filter IS cycled but the plants are absorbing the nitrates (as WB suggested) my fish will be fine, AND in the scenario that my filter IS NOT cycled, my fish will be fine with daily 50% changes until I can somehow solve the problem.

 

[Robbo89]

Any ideas guys

 

[eaglesaquarium]

More information is necessary... Continue daily tests.  Don't do the 50% daily water change... Do the water change only if you see ammonia or nitrite.  The amount of plants you have shouldn't be able to use up ALL the nitrate, so a reading should show up eventually.  
 
You are shaking the nitrate test kit bottles for the full minute and the test tube for the full 30 seconds?  (Another option would be to take your water to be tested by the LFS and see if they can give you a nitrate reading of any kind.)
 
 
If the nitrates (or even ammonia) were being used by the plants, you should be seeing some significant growth in the vallis, for one.  Do you have a picture of it from about a week ago to compare to its current state?  If not, start a photo journal of the tank, focusing on the vallis, but the whole tank too.  The vallis should be the give away to nitrogen consumption by the plants.

 

[Robbo89]

I have very very significant growth in the hygophilia, but not too much visible growth in the val from what I can tell. Will take some water to my lfs on friday to be tested, and yes I am one hundred percent sure now that the tests have been followed with excessive precautions . 
 
Why is it that you advise against daily water changes eagle? Surely they can't do any harm? I'll hunt for some pics and be back soon.

2 weeks ago:

 
Yesterday:

 
I'll grab a snap of the val tomorrow, to compare to the photo ive already posted which is about a week old. 

 

[eaglesaquarium]

They won't do any harm. But if you are trying to figure out where your nitrate is, doing 50% daily water changes will make that nigh unto impossible.

 

[Robbo89]

Ah fair enough, I'll just keep testing daily then and change water accordingly.

 

[Robbo89]

Got some good news, but I'll save that for later, here are the results from yesterdays tests:

 
And Nitrate definitely (and unfortunately) still 0, sorry I forgot to grab a photo of it though. 
 
pH: 7.4 ... (strange?)
Ammonia: 0ppm
Nitrite: 0ppm
Nitrate: 0ppm
 
Anyway, turns out BOTH of my separate orders for this weekend were delayed due to the supplier of the petstore (8x black widow tetra) and the breeder having to work on saturday so he cant make the three hour trip up to my city (2x Peppermint BN). So at this point in time it looks like the tetra will be in around 6 days from now, and the BN just over a week. PHEW!  

 

 

 

 
Even better still! A not so local lfs offered to help me out and give me a chunk of their mature filter wool tomorrow! Which changes everything

Now, I can be confident in the cycling of the tank, and happily add the new fish to a somewhat semi-mature filter!

 
With these things in mind, my questions are:
1. Is there any benefit/reason for me to not perform daily water changes? (I've honestly got nothing else to do around here, and I enjoy it)
2. Would you advise I continue daily tests on the parameters and still post them here just in case something weird happens?
3. Is this photo cute or what...

 

[eaglesaquarium]

1 - I can't think of a reason.
2 - Continue daily tests until you can be certain that you are fully cycled - then switch to a weekly schedule.  No need to post daily the results, just when something weird does happen.
3 - Yes - that's a FOTM candidate, once you are eligible.