[Jon Lazar]

When an unexpected death occurs in a new tank o' fish, the first thing I would suspect is the biological filter isn't up to task yet. I would check ammonia and make sure things are safe. You might consider investing in one of those ammonia badges that sticks to the side of the tank.

[scubanerd13]

I checked the nitrite and nitrate as soon as I saw the fish was dead, just to check for a spike, and to see if I needed to do an emergency water change. I didn't see anything, but I don't have an ammonia test kit at school. Could the fish have possibly been weaker than the others, and not gotten food, or just stressed? What could I look for to twll me why he died?

[F&Fmgr]

also check KH as well as ammonia. I like keppeing the KH higher in a fish only tank, especially with high density, as to avoid a build up of carbonic acid that will lower your pH.

Sean

PS sorry to hear about the fish loss :-(

[scubanerd13]

Due to the big series of storms coming in this weekend, I'm trying to figure out what to do with my fish. I'm going to go in and talk to Sean at Fins and Feather tomorrow, before the storm hits, but I thought I would post it here too. Would it be safe to keep them in the 5 gallon bucket for a few days like I did when I was moving them to the school? or should I try to transfer the fish from the large 55 gallon to the smaller 20 gallon, and just move the filter over from the main aquarium to the small one? what do you think?

[L8 2 RISE]

If possible, leave them, otherwise, definitely the latter.

[scubanerd13]

OK, here's a quick update:
over the long snow break no one was able to get to my fish for over a week. We lost 1 fish, which I later found out was eaten by the other 10. (Yay for cannabalistic fish living in my classroom!)
I went to F&F and picked up and ammonia test kit, which has been a life saver. My ammonia was realy high after the snwo break, and I was able to test and do a water chang to bring it down.
I lost 1 more fish last week, cause unknown. I have a feeling that as it was one of the runts of the school, it was weaken by not having food for a week, and he just died now. Any ideas?
I've been trying toget into F&F for a few weeks to order replacement fish, but Sean has been sick, and we keep missing each other. I hope you and your daughter are feeling better now!

[Origami2547]

scubanerd13, on 02 March 2010 - 02:35 PM, said:

OK, here's a quick update:
over the long snow break no one was able to get to my fish for over a week. We lost 1 fish, which I later found out was eaten by the other 10. (Yay for cannabalistic fish living in my classroom!)
I went to F&F and picked up and ammonia test kit, which has been a life saver. My ammonia was realy high after the snwo break, and I was able to test and do a water chang to bring it down.
I lost 1 more fish last week, cause unknown. I have a feeling that as it was one of the runts of the school, it was weaken by not having food for a week, and he just died now. Any ideas?
I've been trying toget into F&F for a few weeks to order replacement fish, but Sean has been sick, and we keep missing each other. I hope you and your daughter are feeling better now!

Any chance that you can have your water tested (ammonia, nitrite, nitrates, and pH) and provide those numbers? What do you mean "really high" when you speak of your ammonia levels? What temperature is the tank kept at? Where is the tank? If it's in school, are you sure that the temperature is stable (is the building temp set back during weekends and breaks)? How much have you been feeding? Are the fish undernourished (and getting thinner) and could you just be losing them one by one, weakest one first? How often do you feed them? These are fairly basic husbandry questions, but I have to ask them since you seem to be new to a lot of this.

[Jon Lazar]

You might also consider buying an automatic feeder if you expect to be away from the tank for extended periods that aren't weather-related. Eheim makes a good quality programmable feeder that works well with flake and pellet foods. Not the best if you want the fish to thrive and breed, but it's better than no food at all.

Jon

[scubanerd13]

Origami2547, on 02 March 2010 - 05:19 PM, said:

Any chance that you can have your water tested (ammonia, nitrite, nitrates, and pH) and provide those numbers? What do you mean "really high" when you speak of your ammonia levels? What temperature is the tank kept at? Where is the tank? If it's in school, are you sure that the temperature is stable (is the building temp set back during weekends and breaks)? How much have you been feeding? Are the fish undernourished (and getting thinner) and could you just be losing them one by one, weakest one first? How often do you feed them? These are fairly basic husbandry questions, but I have to ask them since you seem to be new to a lot of this.

Ammonia was tested at 0.50 today. What I called "really high" after the break was water was a reading of 1. Nirtite is 0.5, and nitrate is 5. The tanks is kept at a temperatue of 80 F, and the temperature does not fluctuate, as far as I know. I've been in the school on weekends, and tracked the temp before I added the fish. The tank is set up in the corner of the room, under a window. It has 2 airstones, 2 heaters, and an over-the-back filter. I know that except for the week when no one was able to get into the school, they are not under fed. I feed them 1 cube of spirulina, brine shrip, and mysis frozen aquarium food every other day, as per the recomendation of Sean at F&F. The other fish have grown visibly since I got them. I think that the deaths could be due to stress. The 1st fish died less than a week after he was put into the tank. The 3rd fish (a runt) died a few days after the snow break, which I know was stressful for the fish. I don't know if the fish in the middle died of natural causes, or if it was killed by the other fish over the break, because the body was eaten by the other fish. I hope that this info helps!

[Origami2547]

Unless your pH is exceptionally low, (7.5 or below), even 0.5 ppm ammonia is considered unsafe. Scroll down to the middle of this page to the part titled, "How much ammonia is too much?" for an idea of how ammonia toxicity changes with pH and with temperature.

http://fins.actwin.c...in-cycling.html

These numbers are general, and not species specific, but you can see how the ceiling numbers for your situation are between 0.1 ppm and 0.4 ppm ammonia. You should strive to be at 0, or no higher than 0.05 ppm.

From the article:

"The following chart gives the maximum long-term level of ammonia-N in mg/L (ppm) that can be considered safe at a given temperature and pH. Again, note that a tank with an established biological filter will have no detectable ammonia; this chart is provided only for emergency purposes. If your levels approach or exceed the levels shown, take emergency action IMMEDIATELY. "

Water Temperature
pH ==>> 20C (68F) ==>> 25C (77F)
_________________________________
6.5 ==>> 15.4 ==>> 11.1
7.0 ==>> 5.0 ==>> 3.6
7.5 ==>> 1.6 ==>> 1.2
8.0 ==>> 0.5 ==>> 0.4
8.5 ==>> 0.2 ==>> 0.1



From the table, you can see that the total ammonia environment is less toxic at lower pH readings. That's because at lower pH, balance between free ammonia and ionic ammonium shifts so that there is less ammonia and more ammonium. Since the ammonia's the bad stuff (ammonium less so), you benefit from a lower pH in this case. Unfortunately, when the school is empty, you don't have the extra CO2 in the air that all us air-breathers create. This alone will cause your tank's pH to shift upward and, in the process, shift the ammonia-ammonium balance toward the more toxic side. This may be part of what's happening. The solution is to reduce your total ammonia levels immediately. I would consider, if your experiment protocol provides for it, immediately using something to bind up the ammonia (like Amquel) or several water changes to bring your numbers down.

At the root of this, however, is you have too much ammonia being generated. Your HOB filters may not be doing the job that you expect them to do. It could be that they're not big enough or that the bacteria population is insufficient. Another very common problem may be that you're overfeeding or that uneaten food is being swept up into the HOB filter where it rots and releases ammonia. You should make sure that your HOB filter sponge or media is free of detritus. Rinse it clean every few days with clean (but not chlorinated) water - you don't want to kill off your bacteria. If you have two HOB filters, stagger the cleanings so you do one and then the other a couple of days later. Hope this helps.