125 gallon catastrophe...

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badassissimo

Candiru
MFK Member
Mar 26, 2008
524
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Mansfield, Louisiana, U.S.A.
I bought a 125 gallon tank about a year ago, prepared it for fish with a nitrogen cycle and some feeder fish, put fish in the tank, ended up moving the tank to a new apartment, and had everything fine up to about a week ago.

I had a 1 foot pacu, a 9 inch albino oscar, a 11 inch albino giant gourami, and a flowerhorn in a makeshift jail because I needed to setup a tank for him to be alone. Beautiful fish with an attitude at 4 inches.

Right now, the oscar and flowerhorn have died. The pacu is dying now. The gourami appears to be holding. I have no idea why the fish are dying individually. The gourami isn't that aggressive and the fish aren't dying on account of that from what I can see.

Before the fish started dying, I had noticed a burning smell in the house. Occassionally a tortilla will burn on the stove and I don't think anything of it. Coincidentally, this was one of those days. The smell didn't go away over night so I started sniffing for a source but apparently the heater was no longer functional and producing quite so potent of a smell. The light on the heater was not on and I knew what had happened, it had broken.

Unfortunately, the water temperature dropped horribly because the outside temperature was about 20 degrees. The water was very cold and I didn't have any heaters for a 125 gallon tank. I bought 2 200 W heaters and used 150 W in addition to the other 150 W and 100 W that were already in the tank to try and bring the temperature up and it didn't come up until the new 300W came in the mail yesterday. The water came up to 75 and then I brought all of them up to 86 where the tank had been.

While the temperature came up, the flowerhorn died. After the flowerhorn died, the oscar floundered and then died. Now, the pacu is dying. I have melafix and salt in the tank to try and cure any disease but the water quality is about the same. Did the cold kill all the bacteria and now the fish are being attacked? Are the fish dying because the temperature didn't come back up fast enough?

Symptoms: listless or unusually calm behavior, heavy breathing, color change due to gill enflamation, tossing and turning maybe because of swim bladder problems, and finally death.

So far, it is just one fish at a time. The gourami is the same as usual. I think this is maybe because the temperature change didn't affect him? This is why I can't decide what the problem is or what to do now that the fish are dying and I seem to have 1 with hopes of 2 left. If It were disease, why doesn't the gourami have any problems? If you have any suggestions, please send them. I don't want to loose my pacu or gourami.

The only other thing I can think of is that maybe the water is too hot now. I lowered the temperature back down to 80 to see if this will help either of them. At one point in time before I had bought the 125 gallon aquarium, my 55 gallon aquarium was running and had a heater burn up and heat the water to about 105 degrees overnight. Only 5 fish survived. In case it has become a concern, these are not DIY heaters. They have been different brands. The latest break has been a 300 W marineland heater. the 2 200 W heaters are tetra and seem to be working but are from walmart and didn't seem to be able to handle the job together. Am I just not having luck with heaters? Do heaters need dry time? Is there some maintenance I don't know about? Because of these problems, I have become more interested in a perhaps more reliable DIY heater. I don't know how I would do it but I am willing to believe that I can do at least as good of a job at heating an aquarium for 5 weeks and then surprising everyone with 40 or 105 degree water overnight.

First thing is first. Please let me know how to help my fish. Thank you for reading.
 
What are the readings for ammonia, nitrite and nitrate? That will tell you what the bacteria situation is.

Stop putting meds in the tank. Meds are stressful, you are treating for random illness for which you have no symptoms and adding to the stress.

Water changes or hot water bottles would have brought and held the water temps up while you were waiting, but that is a mute point.

You are describing a massive bioload. How often are you changing the water?


If your heater is ever turned on while out of water, that will kill it. As in, the heater is centered (vertically) in the tank, and is only half submersed during a water change.
 
I've had a recent string of bad luck with heaters too. I had a Marineland one die so I bought Rena Smart Heater to put inline with my XP2. That died (Temp Sensor always claimed too warm) and now I have a Hydor Theo 300W in my 55.

As far as I know the temp could have very well been the start of all this. I don't think cold temps will kill all the bacteria. I think you're on the right track for curing your tank though.
 
nitrite, ph, and alkalinity are in check. The water hardness seems to be the biggest change since last I checked. Nitrates are high but I think that is the uneaten food. Only one fish is eating now. I will be cleaning out the excess food and waste tomorrow again. Hopefully some water changes can solve the hardness?

Using a 5 tests in 1 quickdip. alkalinity is 300 ppm and nitrate is 160 ppm. I use an RO filter at the house and let the water sit and aerate for 24 hrs to make sure there is no chlorine. The company only guarantees 12 % remains and the overnight aeration is supposed to take care of all chlorine. I haven't tested positive for any chlorine yet using this method. Would the alkalinity and the nitrates be the cause of all this? I can't tell because I have had fish survive worse than this when moving tanks and residences. All suggestions are appreciated.
 
nitrates are obviously too high, your goal should be to keep them 20ppm or less . . . how is your aeration? it's noteworthy (to me) that your gourami is relatively unaffected, since gouramis are able to surface-breathe

could be that conditions in the tank were already on-the-edge, and the sudden fluctuation in temps - - from hot to cold and back to hot again - - triggered these deaths
 
If your nitrates and GH are both high the problem is solved. You just created osmotic shock.


You have not been changing the water but have been topping it off. Your nitrates are even higher, your kit just maxed out at 160.


You need to start with really small water changes. Do daily 10% changes for a week, then do daily 20% changes for a week.

After that weekly 50% changes are your friend.

Throw out your dip sticks and go a get a liquid reagent test kit.


FYI you fish have NO immune system right now. Nitrates that high stops all production of white blood cells. Adding anything to the tank (new fish wise) will wipe out the tank. The Chemicals you added might do that for you anyway.
 
They are hardy. I've seen them kept with koi. I thought pacus and oscars were too though.

I thought I'd been good to go on water changes. More is better I guess. Is more than 10% a day worse? That's only a little bit more than I do in a week. Is there a good reagent test on the internet? www.drfostersmith.com is the place I usually go for anything. Please let me know. Thank you.
 
I'm going to see if I can slide the tank out and lift the bed filters to clean under those. I'm willing to bet that bed filters have more than I've found recently. I should have checked that better.
 
At this point a massive water change will cause more trouble. You need to get your nitrates BELOW 20ppm. Doing that in 3 water changes will kill the tank. You need to do that slowly, but then once its there... keep it there.

Water test kit: I really like the API fresh water master test kit. Drs foster and Smith do carry it. Any liquid reagent kit is fine though, I just like API.

Hows your water flow under those "bed filters" (I presume you mean a UGF)? Are they run by air or power heads? Are they running?

Lifting those filter beds up will shock you, its REALLY gross under there. I would wait to lift those up until your water is ready for the 50% change. Do the smaller changes for 2 weeks first, then when you have the nitrates low enough to do a 50% change... lift the plates and clean under them. Heck if you have the nitrates under 30, do an 80% change to clean out from under the plates if you'd like.

Dropping the GH by more than a few degrees at a time is really rough on the fish. Once you have done enough water changes to get them down to 5 or 6, a 50% change will only lower them by 2 or 3 degrees. If they are currently at 15, a 50% change will probably kill the fish.
 
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