What killed them?

Last week, I had a bit of a catastrophe in my tank. It's a 3ft/100l tropical community.

I had a fair number of bottom dwellers in the tank, including 2 green phantom plecs, an ornioco angel plec, a snowball plec, starlight ancistrus, 2 normal ancistrus, 4 peckoltia brevis, 4 whiptails and a couple catfish. I know the bottom of the tank is quite crowded, but I do have 4ft that will be set-up soon and the fish will be spread amonst the tank. I'm also aware the plecos have a pretty big gio-load, so I tackle this with 2 15% waterchanges per week and rinsing the filter sponges in dirty tank water. I add MicrobeLift Ammonia Remover and Stress Relief products on every wc and I add their bacteria-in-a-bottle at a 50% dosage once a month or so.

The fish were doing great, eating well, no fights and all was going really well in the tank.

Last Thursday, I decided to give Flourish Excel a bash. I add Bio-Elite Aquarium Plant Grow 2-3 times a week and the plants do ok, but I figured the addition of Excel would really help the plants grow well.
I followed the directions on the bottle and added 2 capfuls for my initial dosage. This is an underdose, since the bottle says I should add 1 cap per 40l for first dose, then thereafter add 1 cap per 200l.
I also gave baby marrow as pleco food for the first time. I blanched them before adding them to the tank and the fish really took to them.

On Friday morning, I heard one of the fish knocking against the canopy, but considering I have 3 hatchetfish, I figured they were just being frisky and jumping a bit. The fish looked ok in the tank, although, in hindsight, my hoplo cat was alot more active than normal and was back and forth across the tank. I did notice the outflow on the filter seemed a bit reduced, so had planned to do a wc and filter-clean when I got home. I had some free-floating plant leaves in the tank, so figured a few where clogging the filter and affecting the outflow.

I went out for 8 hours and upon returning home, found both both my phantoms, the ornioco, snowball and my male krib all dead and bloated. The kribs looked like a normal dead fish, but all the plecos had red discoluration on their pectoral fins and one phantom had redness on his mouth. None of my live fish showed any discolouration.
The hoplo was still missioning around the tank and when I lifted the canopy, one of the hatchets made an escape attempt and hopped out the tank. I recued him and put him back in the tank.

I did a 30% wc immidietly and as a precaution, took my filter out and replaced it with a more powerful filter (I actually couldn't get the original filter open for some reason, but there was clearly a fair bit of sludge on the sponges) that I had lying around. I added all the MicrobeLift products and so far, so good. No more deaths and the fish are acting normal again.

So, what could have killed my fish so suddenly? Could it be toxins coming from the filter, the baby marrow (unlikely?) or the Excel? Since this all happened, I have read in a couple places that plecos can be particularly sensitive to Excel, but I even underdosed, so not sure if it would have affected them? I'm wondering if they got burned by the product or something, considering the discolouration.

Any advice or ideas? I'm gutted about the plecos! I have a pH test kit and the pH is around 6.5. I don't have kits for other chemicals though and the tank smells normal, if that makes sense.

Cake for anyone who made it to the end of the essay.

 

I might add, I dosed the Excel on Thursday night. Not sure if the timeline makes a difference.

 

uhm, i gave my fish cucumber and after a few hours my water spiked heavy, ammonia.

 

No, as I don't have the test kits.
Am heading the lfs today though, so will take some waterwith and see what they say.

So it could be an ammonia spike from the marrows?

 

i really don't know, im just saying that it happened to me

 

From my experience plecos do seem sensitive to Excel.I have lost baby plecs 24 hours after dosing.
Baby marrow if not prepped correct will block the filters, leading to problems.
For adult plecos i blanch to a semi hard extent so there is minimum mush in the filters.
Feed at night and remove any uneaten marrow the next day.
If the filters do get blocked i clean them out immediately.

 

thats completely overstocked

 

There is 2 options here:

Firstly, you are using 3 different types of products here, Microbelift, Bio-Elite and now Seachem. I always advise people to try and stick to one single brand, purely because no matter how "natural" the guys say their products are, they will never give you a written guarantee that their products can be used in conjunction with other brands. So it is possibly that the Excel has reacted.


The second option is more probable.
You have an extremely high bio-load (i.e severely overstocked), you admitted to your filters appearing blocked, and I think 2 x 15% WC is not enough. ESPECIALLY considering the stock you have are his mess fish. You should be looking at a minimum of 2 x 40-50% per week.

I believe the water ammonia, nitrites and nitrates to have climbed to levels that are poisonous to your fish, weakening their immune system. As Khalid indicated, pleco's can me sensitive to Excel, and thus the new addition of Excel to an already weakened immune system was the final blow to them.


My immediete suggestion would be to firstly sort out the filtration. I sincerely hope you did not start a new filter with unseeded filter. Do 50% WC every second day with AGED/HEATED water. And get the big tank set up.

 

Thanks guys.

The new filter has one of the old filter sponges in it and then a new sponge too and its turn-over is 800lph. Will try get the new tank up this week and cycled as asap and get this all sorted.

 

@Xandoz NO that sucks!!!!!! those poor Pleco's hope you get to the bottom of it find out what happened

 

Get some proper Bio-filter media like seachem's Matrix. Sponges on their own is not really suitable, especially on that tank.

 

And I would suggest increasing your water changes....as water changes plays the biggest role, even bigger then filtration.

 

What did the water smell like ?

 

Water smelt like baby marrows. No chemical smells. And before the marrows, it smelt like normal tropical tank water.

@Zoom, the matrix: where should I put it in the filter. It's a SunSun internal filter with 2 compartments for sponges. Should I cut a sponge in half and do half spong/half matrix in the compartment or should I replace one sponge completely with matrix?

 

AS for canister and filter media ... do a full layer of 1 type of media now if you can layer two types of media in one sleeve / container that is fine, but do things in layers - if you do not do layers then water will take the path of least resistance.

Depending on the design, sponge is a big mechanical filter pad of sorts - should be easy to reach into the unit and clean just that while leave the rest of the media intact - I do not have a sunsun but I hope this makes sense interms of the sunsun design.


Ahhh smells ... so if you do not have any test kits then learning what a healthy tank smells like is the next best thing.

When the pollution or allergens d0 not get the better of my nose, I aim for for a earthy smell in my tanks (careful cause this can also be the smell if you have loads of BGB). Water with no smell (investigate, except after a big slow WC is always suspect), one that has a hint of fish (probably needs WC to flush the system), slight dead egg (substrate going bad or debris build-up), nose of death ( look for the corps) etc ..

hmm what temp was the tank running at, high temps means quicker decomposition - but also has an affect of less oxygen available in the tank but since excel becomes carbon, hydrogen and oxygen + some OK misc stuff ... I m not sure it was the excel.

Now the smell like baby marrow - I have only seen this when the tank was running seriously hot and the marrow was pulp in a short time. Wonder if the marrow did not carry another toxin into your tank?

Sorry about the loss, sometimes these things help the tank to find a balance in stocking level etc.

Later Ferdie

 

Thanks Ferdie. I'm also thinking the main culprit was the marrows. I've thrown the remainder of them away. Too scared to feed them to the fish now.
The tank's temp is 26C.

 

http://www.tropicalaquarium.co.za/s...-Excel-(Gluteraldehyde)/page6&highlight=excel