[Cichlider23]

Hi, I recently setup a new 55 gallon tank and transferred my fish from my old 20 gallon tank to the new one. Over the course of 2 weeks, all but 3 died. Many seemed to die from HLLE or hole-in-the-head, but the fish that died also did not eat once in the new tank. I don't understand why.

I have a 55 gallon tank. Dimensions: 48 in L x 13 in W x 20 in H. It's this tank: Top Fin Essentials
I also have two bubblers, an extra filter from my old 20 gallon and a circulation fan. The tank has cichlid sand to buffer the ph, caribsea aquascaping rocks and pvc pipes to make caves. These are the rocks: CaribSea_South_Seas_Aquascaping_Base_Rock_Dry_Rock_for_Saltwater_Reef_Aquariums

What are your water parameters: Temperature: 82-84, ammonia 0ppm, nitrite 0, ph 8.2-8.4, don't know GH, don't know KH and nitrate 0.

The fish are mostly mbunas. I had 3 kennyis, 1 demasoni, 2 red zebra, 1 venustus, 1 speckled peacock of some type and 1 syno catfish. All but two of these fish were in the 20 gallon tank for 1-5 months. They ate in the old tank. I have always fed them API Cichlid Pellets, but after some time of them not eating in the new tank, I began to mix it up and try some new foods as well, which were new life spectrum (nls) float and nls cichlid pellets, as well as some bloodworms. The fish wouldn't eat it. A week after I put my old fish in the new tank, I introduced two new fish: the syno and a larger red zebra. Shortly after, fish began dying. However, at this point, they hadn't been eating for over a week, so I'm hesitant to blame the introduction of two new fish. I had a new fish die every other day about. The red zebra died 2-3 days after I put him in.

When the fish died, they would start leaving their holes and start swimming near the top of the tank. Then they would began gasping for air a lot, have trouble swimming, and die. Several had marks on their head and lips as they got closer to death and the red zebra had a large hole in its head. After seeing the large hole, I began to treat for hexamita, or hole in the head, with metronidazole (seachem metroplex). The fish seemed to die slower after this, but I still had two die after beginning treatment. I only have three left. I have a venustus that eats everytime I feed them and eats a lot. He seems totally unaffected by whatever got the other fish. I have the speckled peacock but he doesn't eat much, if at all. The syno catfish I see eat bloodworms.

When I first introduced the fish to the new tank, the nitrites spiked high, to about 5 ppm, but I quickly treated it with a 50% water change and treatment with prime (which lowers nitrites). Within a day or two, the nitrites were at 0 and remained so. The fish still would not eat though.

I change 25% of the water once a week and I use seachem prime to treat my water.

I tested for stray voltage, but the voltage in the tank was only .5 volts; my multimeter is extremely sensitive and measures .25 volts between ground and the air, so I think .5 is rather negligible.

I'm still treating with metronidazole.

I cleaned out my 20 gallon and cycled it again. It's finally cycled and I put two small mbuna in there today and they immediately ate. I'm wondering if I should put my remaining peacock that isn't eating back in the 20 gallon, though that tank is really too small for him.

Why are nearly all of my fish dying?

 

[marten]

Sorry to hear about your troubles and losses. The only thing that seems odd to me, is having 0ppm Nitrate. That could mean an incomplete cycle, but I think the API test kit can show 0ppm if you don't shake the second bottle really well. Also if the tank cycled with the fish in it, they might have been exposed to high levels of Ammonia and/or Nitrite, but adding Prime should have helped with that. Also, what are the water parameters for your 20 gallon? Maybe the two tanks are really different and the fish are not acclimating well?

There are lots of people here with more experience than me, but I would start with testing the water again. You should see something like 0ppm ammonia (i think 0.25ppm if using prime), 0ppm nitrite, and at least some nitrate (preferably 5 - 20ppm)

 

[gbin]

I know you said the 55 is new, but I just thought I'd check to make sure: Is it truly new, or just new to you (in other words, used)? Seems the problem must be either the water or the tank, so I'm making sure the tank can be ruled out.

Gerry

 

[Cichlider23]

I tested for nitrates again and the test kit is showing 0-5ppm. I attribute the low nitrates to the tank being understocked and the fish not eating, and therefore not producing much waste. I also have two mossballs, which eat up nitrates i think, and an extra filter. I'm pretty sure the tank cycled; the nitrites and ammonia spiked high initially during the cycle and then eventually came down to 0 for good.

I actually totally reset the 20 gallon tank, with new sand and even a new filter. It's cycled now and I added some new fish to it and they all eat and swim around normally. When I added new fish to my 55 gallon (meaning fish from the fish store, not from my original 20 gallon), they wouldn't eat. The only difference between these two tanks now is the ph is 7.8 on the 20 and 8.0 - 8.2 on the 55. However, before I reset the 20, the ph had been 8.2 in that tank.

My only guess is that I put too many fish in too early, before the tank was totally finished cycling, and that exposure to high nitrites caused them to all get sick, which persisted even after the tank finished cycling and nitrites and ammonia were testing 0. Or, there is just something strange wrong with the tank or the things I have put in it. I've heard of tanks being made with "bad glue", which leeches into the water and kills the fish.

The 55 is entirely new. Came straight out of the box.

 

[Old Newbie]

Did you clean the tank prior to filling it? If so, what did you use and how well did you rinse; if not, it may be something that was in the tank when purchased.

 

[Cichlider23]

I cleaned it only by rinsing with water and wiping down. I was afraid to clean it with anything else because I was afraid residue would leak into the water.

If this was the case, that there was something in the tank when purchased, what would I do at this point? Break it down entirely and clean it thoroughly? What should I clean it with? Would I need to get new sand/rocks/anything else?

 

[andydroid2015]

some fish die due to the types of bacteria accumulated in the pond