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400l mixed community

Well fair to say one of the biggest fish keeping disasters I’ve ever had was narrowly avoided last night.

I broke my bubble counter the other day so had to replace it with new. The bubble count was always high on this tank due to the size but I must’ve knocked the regulator and adjusted it further without realising. I left the tank for around an hour or so and came back to complete carnage. Fish all across the surface, others spiralling and corydoras all on their backs motionless. I thought I’d killed the whole tank. Proceeded to change water as fast as I could and add extra air pumps and raise the filter outlets. This seemed to do the job and it appears I saved everything apart from one cardinal tetra in the nick of time. Everything seemed ok this morning but the dicrossus seemed to struggle more than others and looked dead at one point so need to check on them.

Can what happened cause any long lasting damage to the fish? I feel awful and I would packed it all in last night if I didn’t save them and I’ve been keeping fish non stop for around 20years or so. CO2 has been removed never to be used again. The ridiculous thing was I was debating getting rid of the C02 before I replaced the bubble counter. It’s just not worth the risk, there are so many special species in that tank. Some that have only made it to the uk a few times so I can’t afford for any more mistakes like this. I’m extremely lucky.

Cheers
 
Glad to hear you got there just in time!

Which part of the reg did you accidentally knock and adjust, the needle valve itself? Or the control knob that adjusts the second stage outlet pressure?
 
Which part of the reg did you accidentally knock and adjust, the needle valve itself? Or the control knob that adjusts the second stage outlet pressure?
The thing is I have no idea, I’m sure I didn’t touch anything but must’ve knocked something somewhere to be able to gas a 400l tank in less than a hour.
 
Can what happened cause any long lasting damage to the fish?
I asked myself the same question a while ago when I had a similar near miss and couldn't find any conclusive answers about it.
There's a few studies out there that referenced short term exposure of lethal levels of co2 (ld50 0f 40mg/l) and others that mention the long term effects of prolonged exposure to levels of (20 mg/l) but these were mainly conducted on marine fish or rainbow trout, these studies were often at odds with themselves and non of them specifically mentioned the longterm effects of short term, high level exposure.

The only crumb of comfort I can offer is that its been almost 3 months since I gassed my fish and they all appear to be healthy, the corys still regularly spawn and the glass cats which were particularly affected go about there business as normal.

Its a good reminder to anybody reading this that when things go wrong with co2 it happens quickly and can often be catastrophic.

Hope all the fish recover 🙏
 
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Hi all,
.......... CO2 has been removed never to be used again. The ridiculous thing was I was debating getting rid of the C02 before I replaced the bubble counter. It’s just not worth the risk, there are so many special species in that tank............
Same for me, no CO2 ever.

cheers Darrel
 
The only crumb of comfort I can offer is that its been almost 3 months since I gassed my fish and they all appear to be healthy, the corys still regularly spawn and the glass cats which were particularly affected go about there business as normal.
That’s good to hear. The fish seem fine today and the added flow from the power heads and air stones seems to have set the corydoras into breeding mode. Crazy seeing that they seemed as if they were near death last night.
 
Also something else to note it seemed to affect cichlids worse than the characins and catfish. Loricariids which I would class as more oxygen dependant reophilic species seemed to ride it out better than all other species which was a surprise.
 
The thing is I have no idea, I’m sure I didn’t touch anything but must’ve knocked something somewhere to be able to gas a 400l tank in less than a hour.

Almost sounds like complete failure of the needle valve to do it that quickly. I've knocked my old CO2Art one before, as they are so flimsy and inaccurate. One of the reasons I always use the Camozzi needle valves now as they are much better quality than the stock ones, and have the locking nut to ensure it can't be adjusted accidentally.
 
I am guessing that it’s common knowledge here, however, single stage regulators, do not maintain constant pressure, as the cylinder pressure drops, the pressure delivered by the regulator can rise considerably
 
I am guessing that it’s common knowledge here, however, single stage regulators, do not maintain constant pressure, as the cylinder pressure drops, the pressure delivered by the regulator can rise considerably
This was a double with plenty left in the tank so it was definitely a mistake somewhere by me.
 
That's a horrible thing to discover but glad things mostly turned out ok, you have quite some fish collection so going the simple route is probably for the best.
 
To be fair since the upgrade to a larger tank it’s never been a proper high tech and co2 stability/distribution has always been an issue hence the bba appearing a lot. I was debating removing the co2 for a while and it’s a shame it took this to do it. I’ve always been more of a fish keeper than aquascaper so this is definitely the best thing to do for the fish.

I was always under the impression I never added much co2 but since the removal some of the tetra species are definitely brighter in colouration. I have also decided to keep an extra power head in there now to be benefit the loricariids.

It’s pretty much my dream tank stocking wise for an aquarium this size so it was silly ever risking the livestock really. Hopefully that’s the end of any drama for now!
 
I'm a big fan of your livestock and am so glad you caught your error before things got more dire. And for all the limitations of not using supplemental CO2, when the tank is well balanced it can feel sort of effortless and robust. It's an underrated quality IMO, especially in a tank where the fish are the stars of the show anyway.

I look forward to the next chapter!
 
Hope everyone’s keeping well.

New plants are starting to fill out now and the tank doesn’t look so bare. Believe it or not I thought I’d removed all the nymphaea in here around 9 months ago. Since the removal of the dense plant mass and floaters they have reappeared everywhere, there must have been some small daughter bulbs in the substrate waiting for the right time to return.

Mum apisto has had another spawn in a pleco cave which she has clever covered with sand to make entrance small enough for only her to squeeze through. I’m planning on removing cave, mother and eggs together into one of the tanks in the cabinet. I’m hoping if I cover the front with my hand and move everything together full of water it won’t disturb the female enough to abandon her eggs. Anyone have any thoughts on this or if they’ve done anything similar with another cichlid before?

Cheers
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I’m planning on removing cave, mother and eggs together into one of the tanks in the cabinet. I’m hoping if I cover the front with my hand and move everything together full of water it won’t disturb the female enough to abandon her eggs. Anyone have any thoughts on this or if they’ve done anything similar with another cichlid before?
Place a pint glass (or large tuppereware) around the cave, hopefully cave is small enough to be engulfed then move entire cave carefully to new tank. Don't take mum, i suspect she may eat eggs if moved.
 
Well fair to say one of the biggest fish keeping disasters I’ve ever had was narrowly avoided last night.

I broke my bubble counter the other day so had to replace it with new. The bubble count was always high on this tank due to the size but I must’ve knocked the regulator and adjusted it further without realising. I left the tank for around an hour or so and came back to complete carnage. Fish all across the surface, others spiralling and corydoras all on their backs motionless. I thought I’d killed the whole tank. Proceeded to change water as fast as I could and add extra air pumps and raise the filter outlets. This seemed to do the job and it appears I saved everything apart from one cardinal tetra in the nick of time. Everything seemed ok this morning but the dicrossus seemed to struggle more than others and looked dead at one point so need to check on them.

Can what happened cause any long lasting damage to the fish? I feel awful and I would packed it all in last night if I didn’t save them and I’ve been keeping fish non stop for around 20years or so. CO2 has been removed never to be used again. The ridiculous thing was I was debating getting rid of the C02 before I replaced the bubble counter. It’s just not worth the risk, there are so many special species in that tank. Some that have only made it to the uk a few times so I can’t afford for any more mistakes like this. I’m extremely lucky.

Cheers
Its a good reminder to anybody reading this that when things go wrong with co2 it happens quickly and can often be catastrophic.
Something similar happened to me last Saturday. When I do water changes after CO2 has started but before light goes on, I usually crank the CO2 a full needle valve revolution for 5min, tops 8min after I do the WC. This is to replenish CO2 in water just before lights go on. Well, I forgot to bring the needle valve to its baseline position. This was only 5 minutes extra from what I usually do. The rasborras and the ottos where already at the top of the tank looking for oxygen. Was lucky I caught it in time and no one died.
With CO2 things can go down south very fast.
 
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This was only 5 minutes extra from what I usually do.
It’s crazy how fast things can turn with C02. My incident was probably less than half an hour in a pretty big tank with surface agitation and everything was nearly dead!

To be fair I’m not even sure me adding c02 this tank was benefiting anything. The inconsistency of the C02 due the way my c02 was distributed around the tank seemed to be negatively affecting it. BBA has receded but not gone completely now and plant health has actually improved. Interestingly light levels are still the same though.
 
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