Fish Crisis!! Please Help, why are my Fish dying??

MollyPlatySwordtailfish

Thanks yet again guys. I just did a test on the nitrite in the tank. And (Drumroll) If says that the nitrite levels are at .50 mg/L. It said anything higher than 0 could hurt the fish. How dangourous is that?

aunt kymmie

Water change time.....

conger

kymmie is right, go ahead and do another water change. A fully-cycled tank will have ammonia and nitrite readings of 0, with some level of nitrates (in general 40 ppm is getting to a dangerous level, ideally below 30 ppm, 20 or below is even better). Since you've got some nitrites in there, do a water change to dilute them down.

You must have done something recently that hurt or destroyed your bacteria population, since you mentioned the tank has been up and running for a couple of years. If the bacteria die off (or you put a bunch of fish in all at once, and the bacteria population is no longer large enough to support the bio-load), the tank will go through another cycle, meaning the ammonia will spike then the nitrites will spike until enough bacteria grow to consume them and keep them at a constant level of 0.

Now what happened to kill the bacteria, I don't know (or maybe you added a bunch of fish recently?). I imagine the medications you added wouldn't do that, but I suppose its a possibility. But, I bet that's why your fish are having a rough go of it, the tank is cycling right now, and the toxic ammonia and nitrites are claiming victims. Just watch the levels and do water changes as needed to keep the levels down, until they stay at 0 by themselves. Then following the advice of others in the thread, frequent and small water changes along with proper filter maintenance should prevent it from happening in the future! Keep us posted on the other test results if you like

MollyPlatySwordtailfish

Ok just got the uh Nitrate test. It says that the levels can be from 40 mg/L to 80 mg/L. It is hard to tell but I think its more toward 40 mg/L how is that for a nitrate level?

aunt kymmie

As Conger stated...ideally nothing over 30 but preferably 20 or under. That reading, along with your nitrite levels indicate that a water change be performed, pronto.

MollyPlatySwordtailfish

Oh No! I just did a water change yesterday! Ok i'll do another one. We did add a whole bunch of fish a like the weekend before this last one. Maybe thats it. The water change shall be done though. One small problem, when I do the change, I like to dig in the rocks with my syphon to get some of the waste out that may be spiking the ammonia levels. But, There are fry in the tank currently(I dont know how, but they live down there and when I was doing the change yesterday I scared a few out and they were eaten. Would it just be fine to not dig in the rocks?

aunt kymmie

Well, if it was my tank I'd do the gravel too. I'd be more concerned with my fish than the fry. The fish will reproduce anyway. Harsh, I know....
I had a similar situation with a mini cycle and it seemed like I was doing a water change every other day, sometimes two days in a row. You have to do what you need to do in order to keep the levels in check and get your tank back on track. If you're siphoning off into a bucket you may be able to net out the fry??

conger

its really good that you got the test kit, now we can see that the tank is cycling and the nitrate level is getting a bit high. And the addition of a bunch of fish recently is probably the culprit .

Just a suggestion for frequency of testing, I'd recommend testing fairly often (every day or two) while this mini-cycle is going on, until you see the ammonia and nitrites at 0, and the nitrates down to a safe level. This will allow you to closely monitor the really toxic stuff (ammonia, nitrite) and know when you need to do another water change to dilute them, which like kymmie stated may be every day or two.

Once you get to that point, you can probably back off testing to once a week... and also can probably cut out testing for ammonia or nitrite, and just do a nitrate and pH test each weekend. If at any point you have reason to believe the ammonia or nitrites might be rising, at that point you can perform those tests to find out. If you set aside half an hour to an hour each weekend to test the water then do a small water change and filter media rinse, you'll probably find the tank will stay sparkling clean and your fish will stay very happy and healthy!

aunt kymmie

Agree w/ Conger 100%-

PS. Conger, LOVE your avatar!

MollyPlatySwordtailfish

Thanks for the advice guys. I just did what kymmie said and I did about a 75% water change. I am going to hold off on the medication and Start testing like you say and see how that goes. Oh and I made a small discovery, When I went to start the syphon to start the water change, the water was very cold. I look at the thermometer and it read a little below 70. Not good. I followed the line from the heater to the outlet and of course it was unplugged. Now would that have maybe killed any other bacteria in the tank?