NickNaylor
Aquarium Advice Regular
Hi everyone,
It's been a while since I've posted here, but I've come running back with my tail in between my legs.
I have a 30-gallon freshwater tank that has been going for about 10 or so months. Since I got livestock in there, everything has done quite well: I still have the same 4 Dalmatian mollies, 10 cardinal tetras, and 3 dwarf rainbows that I started the tank with.
...or I did.
I originally planted the tank, but my plants barely survived and gradually died over the following months. I was using a regimen of SeaChem products - Trace, Flourish, and Excel - but the plants just weren't doing well. I decided to rip everything out and got a high-tech CO2 setup that I got going on Friday. I also took out a bubble bar that I had in the tank; I did this for a couple of reasons, but primarily because the noise of the air pump was annoying.
So, the CO2 setup got going without much issue. I also picked up 10 additional tetras (not sure of the variety - they're primarily silver with red tips on their fins) which I added to the tank on Friday. I started the CO2 off at 1-1.5 bps running for about 9 hours a day, controlled with a solenoid. My drop checker with a reference 4 dKh solution was light green. I also switched to a new PPS fertilizer regimen.
Then the problems started. Several hours after I got everything set up and added the new fish, two of the new tetras died. Though sad, this didn't bother me too much - I chalked it up to the transition, and I had never bought fish from this LFS so I was expecting some hurdles. Over the rest of the day, there were no other issues, and the fish otherwise looked fine. I added a dose of StressCoat given the two deaths in the hopes that this might calm things down.
Then I wake up on Saturday, and one of my beloved cardinal tetras is dead at the bottom of the tank. Ah! I checked my parameters and everything looked good - no ammonia, no nitrites, nitrates around 20, dKh at 7, all of which are typical of my tank - and the only thing that had changed significantly was the pH. My tank usually runs around 8.0 or so, and on my check it was closer to 7.0. I obviously I expected some degree of a pH drop, but I wasn't expecting that big of a drop. I slowed the CO2 down to about 1 bps, possibly a bit less, and kept it going.
On Sunday morning, another dead cardinal tetra. I continue to chalk up the deaths to the pH, but as my drop checker is looking ok and the rest of the fish seem perfectly fine, I'm not too worried. There are also no clear signs of CO2 toxicity - unless I find them dead, the fish seem healthy, their behavior is normal, they're not hanging out at the top of the tank, etc. - and so I figure that the pH change has just been a bit rough on them.
No deaths on Monday morning. I wake up today, however, and I can only find 4-5 of my cardinal tetras (remember, I started with 10 on Friday). I don't see any bodies so it's possible they're hiding in the corners, but I looked pretty well for them and wasn't able to find the others. One of the cardinals had some clear discoloration on its body - like a ring of pale scales around the back half of it's body - and seemed a little lethargic. I don't know what to make of this.
Now I'm in a panic as 1) I loved those freakin tetras and I don't want to lose any more of them and 2) I don't want to lose my larger fish.
Right now, my potential causes for this are:
1) CO2 toxicity - ruling in favor of this are the start of problems since beginning the CO2; ruling against this are the fact that, except for the fact that my fish are dying, they otherwise seem to be behaving normally when I watch them
2) Hypoxia - ruling in favor of this are the fact that I've started CO2 in addition to removing bubble bars that I previously had in the tank; ruling against this are, again, no clear signs that I would interpret as suggestive of hypoxia (e.g., hanging out at the top of the tank)
3) Stress from pH change - this is my leading "diagnosis"
My plan moving forward is to 1) place one of my bubble bars back in my tank to get some O2 into the water and 2) really turn down my CO2 until everything stabilizes. Any other suggestions for what might be going on or other potential causes? Things I should do to try and fix this in the meantime? There is no evidence that I have a CO2 leak or that there's otherwise been an injection of a large amount of CO2 from what I'm able to tell. I suppose this is possible but I have nothing to suggest that this is the case.
Thanks for the help.
-Distressed aquarist
It's been a while since I've posted here, but I've come running back with my tail in between my legs.
I have a 30-gallon freshwater tank that has been going for about 10 or so months. Since I got livestock in there, everything has done quite well: I still have the same 4 Dalmatian mollies, 10 cardinal tetras, and 3 dwarf rainbows that I started the tank with.
...or I did.
I originally planted the tank, but my plants barely survived and gradually died over the following months. I was using a regimen of SeaChem products - Trace, Flourish, and Excel - but the plants just weren't doing well. I decided to rip everything out and got a high-tech CO2 setup that I got going on Friday. I also took out a bubble bar that I had in the tank; I did this for a couple of reasons, but primarily because the noise of the air pump was annoying.
So, the CO2 setup got going without much issue. I also picked up 10 additional tetras (not sure of the variety - they're primarily silver with red tips on their fins) which I added to the tank on Friday. I started the CO2 off at 1-1.5 bps running for about 9 hours a day, controlled with a solenoid. My drop checker with a reference 4 dKh solution was light green. I also switched to a new PPS fertilizer regimen.
Then the problems started. Several hours after I got everything set up and added the new fish, two of the new tetras died. Though sad, this didn't bother me too much - I chalked it up to the transition, and I had never bought fish from this LFS so I was expecting some hurdles. Over the rest of the day, there were no other issues, and the fish otherwise looked fine. I added a dose of StressCoat given the two deaths in the hopes that this might calm things down.
Then I wake up on Saturday, and one of my beloved cardinal tetras is dead at the bottom of the tank. Ah! I checked my parameters and everything looked good - no ammonia, no nitrites, nitrates around 20, dKh at 7, all of which are typical of my tank - and the only thing that had changed significantly was the pH. My tank usually runs around 8.0 or so, and on my check it was closer to 7.0. I obviously I expected some degree of a pH drop, but I wasn't expecting that big of a drop. I slowed the CO2 down to about 1 bps, possibly a bit less, and kept it going.
On Sunday morning, another dead cardinal tetra. I continue to chalk up the deaths to the pH, but as my drop checker is looking ok and the rest of the fish seem perfectly fine, I'm not too worried. There are also no clear signs of CO2 toxicity - unless I find them dead, the fish seem healthy, their behavior is normal, they're not hanging out at the top of the tank, etc. - and so I figure that the pH change has just been a bit rough on them.
No deaths on Monday morning. I wake up today, however, and I can only find 4-5 of my cardinal tetras (remember, I started with 10 on Friday). I don't see any bodies so it's possible they're hiding in the corners, but I looked pretty well for them and wasn't able to find the others. One of the cardinals had some clear discoloration on its body - like a ring of pale scales around the back half of it's body - and seemed a little lethargic. I don't know what to make of this.
Now I'm in a panic as 1) I loved those freakin tetras and I don't want to lose any more of them and 2) I don't want to lose my larger fish.
Right now, my potential causes for this are:
1) CO2 toxicity - ruling in favor of this are the start of problems since beginning the CO2; ruling against this are the fact that, except for the fact that my fish are dying, they otherwise seem to be behaving normally when I watch them
2) Hypoxia - ruling in favor of this are the fact that I've started CO2 in addition to removing bubble bars that I previously had in the tank; ruling against this are, again, no clear signs that I would interpret as suggestive of hypoxia (e.g., hanging out at the top of the tank)
3) Stress from pH change - this is my leading "diagnosis"
My plan moving forward is to 1) place one of my bubble bars back in my tank to get some O2 into the water and 2) really turn down my CO2 until everything stabilizes. Any other suggestions for what might be going on or other potential causes? Things I should do to try and fix this in the meantime? There is no evidence that I have a CO2 leak or that there's otherwise been an injection of a large amount of CO2 from what I'm able to tell. I suppose this is possible but I have nothing to suggest that this is the case.
Thanks for the help.
-Distressed aquarist
