# How to proceed after tank infection



## DementedDave (Jun 27, 2007)

This seems like it would be a common question, but a search of the forum didn't turn up any results.

I've had a nicaraguan cichlid in a 20 gallon tank for about 2.5 years now. I came back from vacation to find he had what seemed to be a pretty serious fungal infection. I treated, but it was pretty far advanced by the time I caught it and he died.

I'm still a newbie aquarist so my question is in regards to the best way to go about preparing the tank for restocking. I'm tempted to essentially start from scratch -- empty the water, replace gravel, buy a new biowheel, and wait until the tank cycles again.

But is that strictly necessary?....my biowheel is well seasoned at this point and I'd hate to throw out the good with the bad. Is it risky to simply treat the water for fungus, do several water changes and restock?

Any advice would be helpful. Thanks.


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## exasperatus2002 (Jul 5, 2003)

You wouldnt need to start from scratch. A large water change doesnt hurt. When I got the plaque earlier this year that wiped out 2/3 of my tank. After I finished treating the tank. I waited a month before I started to restock to make sure everyone else was fine.


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## Robin (Sep 18, 2002)

Most fungal and bacterial infections come about as a result of the fish's immune system already being compromised in some way so starting from scratch would not garuntee that future fish wouldn't get something similar. The best way to keep your fish healthy is to practice good tank maintenance and fish care. Weekly partial water changes, feeding the proper diet, keeping water parameters perfect, stocking the tank with compatible species and male/female ratios,etc.

On your bio-wheel: unless there are still fish in the tank then the tank is no longer cycled. Your bio wheel/bio filtration needs something to feed the beneficial bacteria or else they die.

If you want to speed up the process of re-cycling your tank try getting some Bio-Spira, or Dr. Tim's One and Only. Both of these products have had very good reports of success.

Robin


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## Malawi Mac (Aug 20, 2004)

Wasn't sure if I should start a new thread or not.

I also have questions regarding the extent to which I should discard or reuse after cleaning after an epidemic wipes out an aquarium community. But I feel like I should provide some background info first, since I am a loss to understand what killed my fish. Hopefully the backgroound info will enable more experienced aquarists to identify the problem.

I have/had two primary aquariums - a 135 gallon tanks of African cichlids and a planted 75 gallon tank with rainbows and Congo tetras. I also have smaller tanks 20-55 gal. that I use for growout tanks and to quarantine new purchases.

About 10 days ago, I noticed that the fish in my 55 gal. African cichlid growout tank were swimming hovered near the surface with clamped fins. I diagnosed the symptoms as a precursor to an outbreak of ich. I treated the tank with API's Super Ick Cure. Within 24 hours, the fish all looked healthy and normal again, so much so that I didn't even bother with the second dose 48 hours after the first one. I was feeling pretty good about myself as a fish keeper, but that joy was soon to be rudely shattered.

The epidemic occurred in my 135. It held a mix of male peacocks & haps, some male & female mbuna (generally more peaceful species), and three large Synodontis eupterus that I had owned for over 5 years. The co-rulers of the tank were a male Red Emp and a male moori, who had been companions for nearly a decade and at about 6-7" in length were quite a bit larger than any of the other cichlids. The tanks had a pile of rocks at one end for the mbuna, and an open swimming area at the other end for the haps, separated by some tall plastic plants. It was filtered by two Aquaclear 110's.

Late last week, I noticed that a couple of the haps/peacocks seemed to be hiding and that the colors had faded. I assumed at the time that one of the mbuna was getting aggressive, and started watching for some indication of same. Also, I noticed one of the cats swimming upside down near the surface. I thought it a bit odd since it was not normal behavior for these three cats, but I've had other Synos in the past that did this all the time. So I didn't think anything of it.

Early Friday evening, I noticed the smallest of the three Synodontis was suspended in an upright position near the surface. It was dead. I noticed other bad signs - one of the other two was in distress and was being picked at by one of the mbuna, and a couple more male haps/peacocks had faded colors. Unfortunately, it was New Years' Day, and PetsMart had already closed for the day, so there wasn't much I could do. I did notice a golden yellow coloring on the belly of the dead cat, which I took to be velvet, and presumed I was dealing with an external parasite. I did use a large net to separate the distressed cat from the rest of the fish.

I got up early Saturday morning and found a dead hap and a dead peacock. I dosed the whole aquarium with API "General Cure" (250 mg Metronidazole and 75 mg Praziquantel per 10 gal. of water). When I got home Saturday evening, the cat in the net was still alive, but was covered in slime. My Ngara flametail was covered with white marks (didn't look like ich, though). I added the requisite dose of Mardel's Copper Safe to the aquarium. Before I went to bed, the Ngara was dead.

When I got up yesterday morning, the only sign of life was a mbuna occasionally emerging from the rocks. I decided to remove all of the rocks and plants to get a better picture of the situation. Removing the rocks uncovered the bodies of all of the remaining haps and cats. But all but one of the 11 mbuna were all still alive. I dragged an old 55 out from the root cellar, put 30 gallons of water in it, and moved the mbuna to that tank. At that point, I surmised I was dealing with an unknown bacterial infection, so I medicated it with both Maracyn and Marcyn 2 (as well as Copper safe to keep any external parasites at bay).

But the deaths continue. The two yellow labs died last night, and I found four more bodies when I got home from work tonight. All I have left are three Metriaclima sp. Manda blues and a Rusty.

Water tests conducted reveal that the pH was too low (about 6 point eight) and the nitrates were way too high (over 200). Ammonia and nitrite levels were 0.

Whether or not I these four survive, I am going to rebuild. What do I need to do to eradicate the pathogens from my tank? I figure bleaching the rocks should do the trick, but what about the gravel and plastic plants? What about the sponges and biological media from the AC 110's? Boil them? I'm not worried about killing off the beneficial bacteria as I can always use some media from a filter in a healthy aquarium. And what should I use to clean the aquarium glass?

I also obviously wish to avoid spreading this plague to any of my other tanks. Should I just toss the nets and buckets I've been using on this mess?

FWIW, I did learn something about the value of quarantining new purchases before adding them to the main tank. I bought a male Lemon Jake and a male Cop. mloto ivory blaze last Monday, and they were still in quarantine when the disease hit, so they are alive and well and will form the starting point of my new community, along with a school of five Ps. acei youngsters from my growout tank.


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## Robin (Sep 18, 2002)

Johnny Mac,

it's always best to start a new topic but I will answer you here. 

Fish will hover at the top of the tank for a number of different reasons, from poor water conditions, to aggression from an other fish to parasitic and bacterial infections. You mentioned that your nitrates were over 200ppm so I would first of all suspect your water conditions were at fault--at least partly.

As far as disenfecting the tank: its not always necessary since much of the time the fish have succombed to a illness because they were first of all stressed. Things like bloat and the common bacterial disease known as Columnaris are illnesses that come from organisms that reside in the tank--harmlessly- until the fish comes under some kind of stress and is unable to fight them off.

But since we don't know exactly what happened in your tank, and for your own peace of mind you can drain it, run a light solution of bleach through it, (1 part bleach to 4 parts water), rinse, rinse, rinse with dechlorinated water and then refill the tank. Throw out the media from the filter. Luckily you have other tanks so getting this tank cycled again will be an easy and quick process. Just take some of the media from one of the established tank's filters and stick it in the 'new' filter. Fish can be added right away but only add 2-3 every couple of days so that the bio filter can gradually build up. You can also 'steal' some of the gravel from one of the other tanks--not as much beneficial bacteria in the gravel as the filters but it will still help.

As with any new tank set up you should test the water parameters daily for the first three weeks.

Robin


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## Malawi Mac (Aug 20, 2004)

What about the plants and gravel?

The plants are plastic so I want to soak them in something that won't get absorbed into the plastic. One of the things I thought of while tossing and turning in bed last night was buying a large bottle of cheap vodka and soaking the plants in it a few at a time. Do you see any harm in that?

I can't think of anything for the gravel other than preparing several buckets of bleach solution, adding the gravel, and then letting it soak.

What about the Python I used to drain the water from this tank? Discarding a couple of nets is no big deal but a replacement Python would be expensive.

Found my big beautiful male Manda blue dead when I got home from work tonight. Two small Mandas and a rusty is all that's left. The rusty actually looks better than he did yesterday. Should I be feeding the fish?

Thanks for the help you have provided so far.


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## Robin (Sep 18, 2002)

Running a light solution of bleach through/on everything will take care of it. Then rinse with water that has a double dose of dechlorinator in it, then let everything air dry.

Most oraganizisms will not survive out of water and the bleach just seals the deal.

And as I said, more than likely your fish died of something like ammonia burn, or Columnaris, or something else that is either ubiquitous to the tank or avoidable with proper maintenance and there's no way to sterilize the tank against that sort of thing.

If any fish survive then once you have the tank all set up I would let them have 3-4 weeks in there for observation and then if all are symptom free, go fish shopping. 8)

Sorry for the loss of your fish.

Robin


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## Malawi Mac (Aug 20, 2004)

One more quick question.

What about cold as a sterilizing agent? Will most organisms that afflict tropical fish survive the extreme cold such as we are experiencing in the Midwest right now?

I'm thinking of the gravel (I could scoop into buckets and leave it outside overnight) and my Python.

Night temps here now are in the single digits F for the most part.


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