Fish deaths

[LGooley]

I am having a problem with my 72 gallon tank. I am losing about 1-2 fish a day for the last 3 days. I have been monitoring the water it is rock steady. ph 7.2. ammonia 0. nitrates 0. nitrites 0. I have city water. Chlorine is 0. Temp is 78-79. I run an AquaClear 500 filter. I changed the carbon filter and sponge filter about 2 weeks ago. I currently have the following fish in the tank: 5 platies, 8 zebra danios, 4 longfin leopard danios, 4 lemon tetras, 4 flame tetras, 2 emerald catfish, 2 corydoras julii, 1 small angel fish (new), 9 gourami & 2 plecos. I typically feed a small amount in the morning and a small amount in the afternoon. My LFS guy could not find anything wrong with my water sample, this confirmed what I had already tested. The only thing that he came up with is the possiblity that I may have done to drastic of a water change a couple weeks ago. I changed between 30-40% of the water because I had been overdue to change the carbon filter by about 2 -3 weeks (they were out of stock at my LFS). I have not noticed any fish not eating. I have lost in the last 3 days: 1 flame tetra, 1 lemon tetra, 1 blue crosby gourami, 1 angel fish (new), 1 khuli loach. Last week I lost 2 corydoras julii. I also have life plants in the tank and many small snails. I am at a loss. Help please.

:(

[snakeskinner]

first off, I find it hard to believe your nitrates are zero. You should have some nitrates from normal nitrogen cycles. Water changes will remove some of the nitrates unless your tapwater already has nitrates. I would look for some type of sickness. Are there any white dots or anything else obvious on any of the fish you've lost? Most of the fish you listed as casualties are fairly weak fish anyway. 30-40% is not excessive so unless you made a radical temperature change you shouldn't have had any problems. Kyle

[dwf73]

How do you treat the water before filling the tank?

[LGooley]

Hi,
Yes they are zero...I have had 3 more deaths since last night. Another gourami, a zebra danio and a longfinned danio. I am going to take another water sample to LFS after work. No white dots, fish eating, no signs of stress. Angel is very quiet (I bought 2. 1 has died). Angel smaller than most of other fish. Will do water change tonight. I am very careful about not dropping water temp when cleaning. I treat new water with Stress Coat by Aquarium Pharmaceuticals. I feel like my aquarium is rejecting all of the fish. I am also going to try a new carbon filter. Any more thoughts would be helpful. I think my LFS is at a loss too.:shake: :sad

[Hound]

Ammonia, nitrite, and nitrates all zero is what I'm wondering about. That doesn't sound natural. I notice in your post you changed the carbon filter and the sponge at the same time. Generally speaking sponges shouldn't get changed all that often. Just rinsed out in declorinated water. Also in a healthy tank carbon filters aren't usually needed. If you did change both at once that should have dropped the bacterial level in your tank by quite a bit and caused a spike in ammonia and nitrites. At least that would be my thinking. You only mention the AC500 is that the only filter you have going on the tank?

[Richer]

How long has your tank been running for? Before you put in your fish, did you cycle your tank?

I highly doubt that your tank has zero nitrates. In freshwater systems, with the exception of moderate-highly planted tanks (or tanks with a good plant filter), there will always be a detectable level of nitrates. My 66 gallon tank is very lightly stocked (only 3 zebra cichlids), I've have enough filters on that thing to run a tank double its size, and I still have detectable amounts of nitrates. So it seems very strange to me that your levels are so low.

If you treat your water for chlorine or chloramine, and your tap water is simliar to that of your tank water, water changes should not affect your tank is such a manner. I do weekly 40% water changes on all of my tanks (or even more often if I get the chance), and non of my tanks have ever experienced die offs.

-Richer

[LGooley]

Hi,
I just got home from work, no deaths in the last couple hours. Here is the update. The only filter I am running is the AC500. I did change both the sponge & the carbon at the same time. My LFS told me to change the carbon once a month & the sponge once every three months. They did tell me to gently squeeze it in a bucket of tank water when I clean the tank. I got the tank in mid December. I set it up, got the temp regulated for about 1 week. I then added live plants about 12. After 1 week I added the 5 platies. After 1 week I added 8 zebra danios...and so on. I have had a few assorted deaths here & there but nothing like this. I have not added fish (until the 2 Angels) for over 1 month (probably 6 weeks). I had a couple deaths before the angels but after the carbon filter/sponge change. The other problem is the carbon filter was about 3 weeks late being changed (out of stock). Anyways...I tested the water 2 different ways tonight. Using the Deluxe Fresh Lab by Red Sea. ph7.2. NH3/NH4 0. NO2 0. I have not done anyother tests with this today but can do the following GH, KH,, FE, CO2 & CL2 (chlorine has been zero). I also as a secondary test used a 5 in 1 strip quick dip by Jungle fish care with the following results: Nitrate NO3: 20 (sorry I was wrong on this one), Nitrite NO2: 0, Total Hardness GH: 75 (soft), Total Alkalinity (KH): 40, pH: 7.2, I also did a quick dip Ammonia and got 0. The water from my tap is treated only for chlorine/chloromine. I do not adjust my ph or anything else chemically or by anyother means. I don't know if this is related but last week I put out a posting titled "flame tetra pregnant?" That flame tetra has not changed. I really appreciate everyones input. I am very new at this and am getting a little frustrated. I hope that everyone understands if I sound grumpy. I am getting tired of burial at sea. Thank you

[Hound]

I'm honestly guessing that when you tossed the sponge and carbon filter at the same time you probably tossed away too much bacteria. With the loss of several fish the balance has probably been restored. I would honestly not change both at once. Well going beyond that I would probably not even change the sponge for a full year. Just rinse it out. Um well, going even further I'd probably use 2 sponges in the filter and not use carbon at all unless I needed to take meds out of the tank.

[LGooley]

Hi,
Just got back from LFS. I have 1 gourami that has some kind of abrasion by its pectoral fin. It looks like it rubbed against sandpaper. It is a small spot almost invisible to see. My usual LFS guy was not in. After multiple water tests and retests they determined that my water is perfect! The guy (have never dealt with him before) recommended a 100% water change and treating the infected fish by itself and then retreat the entire tank with Hex-a-mit antibiotic capsules. I am not sure if this guy knows what he is doing. I felt like he was guessing. Need Help.

[Hound]

To be honest I think we are all guessing at this one. Keep in mind that if you do medicate you will need to remove your carbon filter for a couple of hours to allow the medicine to work.

[snoozin]

I'm fairly new at this (at least recently) but doesn't doing 100% water change add to the risk of a re-cycle?

[LGooley]

Hi,
I lost my favorite fish last night, Blue/red/black varitus platy. It was one of the first fish in the tank. I medicated this morning. I pulled the carbon filter & kept it out all day. No more deaths since I medicated. I also did not feed this morning. Everyone keep your fingers crossed. Hopefully this will work. Thanks to everyone for all the support. Letty

[Hound]

I don't think a 100% water change would screw up a cycle too much, but it would stress the heck out of the tanks residents. One of the reason for small water changes done often is to maintain a balanced tank.

[Richer]

Hound - thats not really true. If done correctly, perhaps the only stressful part of a water change is having a person constantly hanging around the tank fiddling with things... and if you're vacumming gravel, perhaps having a tube moving throughout the tank. However, if you're only doing a water change, then you can probably think of ways to minimize yourself from hanging around the tank. Just make sure that the water going into the tank is simliar in temperature, and pH, and your fish will be fine. I do two 50% water changes in a row once every 1-2 months, and I do 50% water changes once a week, and all of my fish thrive. The zebras in my Malawi tank have bred countless amount of times (though I've never bothered trying to catch the fry in that tank, so they end up getting eaten), and even the tetras in my planted tank have bred several times.

In a nutshell, the more often you do a water change, the more similiar your tank's water will be compared to your tap water. So in an emergency, you can easily do a 100% water change without much fear.

HTH
-Richer

[LGooley]

I may have to do that. My tap water is very similar to the tank water. I just lost another fish. I have now lost 5 gourami's. The fish with the abrasion is still alive. I seem to be losing mainly gourami's & tetra's now. Although it is hard to guess. I did the antibiotic treatment this morning. The tank is getting pretty empty now. I have a feeling the whole tank is going to die and I will just be starting over. Of course at this point I am getting pretty tired. I am still looking for as many suggestions as possible. I bought a python last night. If I have to do a 100% change I don't want to do it by 5 gallon bucket. At what point should I consider the tank a total loss and euthanize the remaining fish?? They don't appear stressed but then I find a dead one in the plants or stuck to the filter intake. I would hate to think they are suffering. This is the part that really sucks!! At least I know what to do when my cats are sick.

[Max]

Not sure about the anti biotics I'd be afraid that it would kill off all the denitrifing bacteria. I know that this is sort of a shot in the dark but, have you added any decorations switched your foods or has your local utility switched to chloromide(sp) from clorine? I'm mostly into salt water so my ideas may not apply very well to fresh water. Also have you performed an autopsy on any of your fish? I know it sounds kind of gross but, that may be the only way to identify an internal macroscopic parasite like a fluke etc.
hth good luck and keep us posted
chris

[LGooley]

Hi,
I lost the other angel this afternoon. However I did not lose any over night last night. The time period between deaths is getting longer. I went to my LFS after work today with another water sample. I thought my nitrates were getting high. They were up to 40. I saw another one of my favorite LSF guys. He spent a lot of time testing and asking questions. He had some new ideas to try. I have done 2 antibiotic treatments now. He wants me to do 2 more. He also had me do a 25% water change. He felt 100% at this point would be to much of a stress on them. After the water change he had me add marine salt to the tank. 1 rounded tablespoon to every 5 gallons water in the tank. Hopefully this will work.

To answer the questions from maxilaria, I haven't changed anything. I added a couple of new fish. It seems that they may have been the catalist. I had a couple of deaths before them, but they seem to be what set this off. Unfortunately they are still alive!

I really appreciate everyones tips and suggestions. I will keep everyone posted.

Thanks,
Letty