[beguiled]

Hello everyone,

For the reasons stated in the title thread I am not having a good morning.... :crying:

I've had an 16 gallon biorb that I initially set up August 2015. It's filled with low-light plants and has been home to two honey gouramis, seven neon tetras, and five amano shrimp since September.

On Wednesday of this week I did my usual water change and added a new heater because the old one just wasn't heating anymore??? The indicator light marked green to say it had reached the preset 78 degree temperature but my thermometer was reading 70 and upon touching the water it definitely felt colder than 78.

Then lo and behold on Thursday, one tetra was floundering. By this morning all of the tetras are dead. The two gouramis were at the surface looking rather limp.

My gouramis are my precious babies and I have quickly netted them out and put them in my 5 gallon cpd tank!!! I would be in deep deep mourning if I lose these. One of them has seemed to have perked up as I'm typing this. I'm trying to remain hopeful.

Of course, I have run the liquid test drops for the water... and everything has come up 0.

Water temp is at a 77.

I don't think Prime dechlorinator failed because I changed ALL my tanks that day and my CRS and CPD tanks are chugging along like normal.

As I previously mentioned, the only thing new was the heater... Could that be the cause?

UGH. I'm so distressed and at my wits end.

 

[Nordic]

You did rinse it off under the tap before putting it in the tank?

 

[mistergreen]

Could be temperature shock. When adding a heater, it's best to increase the temp slowly over time.
Best course of action is not to keep changing temps. Leave it alone and hope the survivors recover.

 

[Diana]

Warmer water holds less oxygen. If the old heater had been failing for a while the tank may have been just a few degrees cooler.
At night plants use oxygen, and release CO2.

The combination of these 2 effects might have lowered the oxygen level, especially in the lower part of the tank. Gouramis can breath air, via their labyrinth organ, but generally prefer warmer air- so they survived, but are not too happy (because of the great temperature change).

 

[beguiled]

Thank you so much everyone for all the responses!

I did rinse off the heater, so I discarded that theory too.

And I never thought that the temperature would rise SO quickly, and because it is preset I couldn't adjust the temperature slowly back to the usual 78 degrees.

But those explanations make a WHOLE lot of sense. Especially explains why the gouramis have fully recovered. Granted I moved them to my CPD tank but I'll introduce them back to the biorb another day so that they don't get so stressed.

Ugh. I'm just so frustrated that I had to learn through such an awful mistake.

 

[Diana]

I would make sure there is plenty of water circulation, at least 5 times the tank volume per hour. More may be better. Up to 10x is fine for many plants, though Gouramis won't hang out in the highest flow parts.

If the 'Bio Orb' cannot provide enough water movement, then do not use it for living organisms.

 

[tapwater]

I suspect you did a big water change before installing the heater. If you did that might be a cause.

 

[Tessa]

I don't know if this could be the case, but I read at a betta forum that some people have had trouble with Aqueon heaters - fish becoming sick or even dying.

 

[roadmaster]

I change water in three tank's each Friday night,and just this past Friday, I could not remember if I added dechlorinator to the last tank I changed water on.
I knew I added the PRIME to the first two, and was near certain I added it to the last one but was not willing to risk fishes so I added the PRIME again.
Just sayin.
I have done it before and lost whole tank of fish to ammonia/chlorine from chloramines in my source water.

 

[EVANATOOR77]

If I am not mistaken, plants take in CO2 and release oxygen, or else we would all be pumping oxygen into our tanks.

 

[thedood]

If I am not mistaken, plants take in CO2 and release oxygen, or else we would all be pumping oxygen into our tanks.

When the lights are on correct. At night it is the opposite, they consume oxygen and release co2.

 

[roadmaster]

When the lights are on correct. At night it is the opposite, they consume oxygen and release co2.

+one^

 

[EVANATOOR77]

That is also true. If you want to be particular about it, in the presence of light, they do both photosynthesis and respiration, and in the absence of light, they only do respiration.

 

[thedood]

One more thing. Some people do pump air into their tanks at night. I have read about this in particularly heavily planted aquariums where the plant mass is heavy enough to cause o2 depletion and that depletion will cause the fish to suffocate and gasp for air and in extreme cases to suffocate to death.

 

[EVANATOOR77]

I can believe it, especially if your bio load is on the heavy side.

 

[beguiled]

I don't know if this could be the case, but I read at a betta forum that some people have had trouble with Aqueon heaters - fish becoming sick or even dying.

It is an Aqueon heater!

... and I'm honestly beginning to think this heater is the problem rather than temperature change and all that.

I've been running this set up for months at that same temperature. My tetras were full grown, healthy, active and wonderful up UNTIL that heater touched the water and they all suddenly died within a matter of hours even though the temperature was raised only by a few degrees.

biorbs run with an airstone and that has always provided sufficient oxygen where by gouramis were never gasping at the surface for air.

I removed the heater last night and did a huge water change again hoping that my remaining shrimp stock can pull through since all the fish are dead.

 

[beguiled]

So I am definitely beginning to think it was the Aqueon heater!

After thinking it was just the temperature that had caused the deaths, I moved my two gouramis back into the tank after acclimating them.

That same evening, I thought they were going to die. They were lying on the bottom of the tank, fins clamped, looking pretty lifeless. I removed the heater, did a huge water change and by that same afternoon they were swimming and eating like normal.

And a day later, they are doing great!

I want to note that the heater never malfunctioned as far as I'm aware. I have a digital thermometer and it was always marking the preset temperature, the water never felt hot to the touch either.

My father has a theory that maybe there was an imperfect seal on the hater that might have been sending minute electroshocks through the water? I definitely had my hand in there and couldn't feel a thing, but I doubt nano fish would need much of a shock to be effected if that was the case.

Anyway, this all just more theories to add to the growing list.

I'm just glad my two prized honey gouramis have made it past death's grip. This was all such a strange episode. All my fish doing fantastically one day, to all dead or on the verge of dying, to the survivors making a full recovery in one evening after removing the heater.

 

[Tessa]

Glad to hear your fish are doing okay and the mystery seems mostly solved.