Fish Dying - Help

[cora]

Ok so I am not sure what happened. I have a 25g tank that has been set up since Jan. The fish were transferred at that time from a 16g. I am running an internal fluval u4.

On Friday night I did a gravel vac, say 10% of the water, and changed the filter cartridges. When I came home from work Monday night, 5 fish were dead and one had fungus. The remaining fish were hanging out by the bubble wall. I added Prime and took out some water, added salt and a larger bubble stone. I also plugged in, without cartridge, my small filter. The fish with fungus has since died and the tank is now cloudy, which would suggest its cycling again? but the water does look quite right, it looks like there is a soap or oily substance on top.

The remaining fish are swimming around but still not looking quite right. I haven't added food to the tank since Sunday, in case it was an ammonia spike.

Any thoughts on what else I can do to help them out? I do have some melafix but not sure, with the water unstable, that I should be adding other medications.

[Kryptonian]

Well a daily small dose, (10%) water change for the next seven days should clear up the cloudyness.  Leave water out in pots over night rather than using chemicals to de-chlorinate.
As for the other fish...is there any signs of fungus anywhere?  How are they behaving  not "quite right"?
As for the oily look to the top of the tank, this might sound odd, but have you tried to place sheets of papertowel flat on top of the water to see if it removes the oily substance?
That worked once for my when someone accidentally dropped someoil in my tank.  Is it possibly that it could originate from your hands? Or someone spilling into your tank something?
BTW TBay is my home town and L.O.T.R. Rocks!

[Saltcreep]

I'm not familiar with what Thunder Bay uses to treat the water, but if it happens to be chloramine, which many communities are using, it will take a very long time to dissipate, certainly longer than overnight. If you're not sure, I would use Prime just to be safe, and start with about a 20% water change ASAP. Maybe another 10% tomorrow. Actually, I'd go with the Prime no matter what - it has benefits other than detoxifying chloramine. I'm betting the cloudiness is pollution, not cycling. That many fish dying in a short period of time is not normal. Any chance there is something stuck in the Fluval which could be causing the problem.

[wandmangels]

sounds like a "cycling" issue..

Water change AND filter cartridges @ the same time..something i will never do AGAIN(been there done it when i was new to the hobby)
you lose WAY to much of the benificial bacteria.
Even tho it was only 10%  of the water 90% of the bacteria are in the filter

[Saltcreep]

sounds like a "cycling" issue..

Water change AND filter cartridges @ the same time..something i will never do AGAIN(been there done it when i was new to the hobby)
you lose WAY to much of the benificial bacteria.
Even tho it was only 10%  of the water 90% of the bacteria are in the filter

All very true, and I'm not saying you're wrong about the cycling, but it's the cloudiness that I wonder about. Like you, I've cycled many tanks over the years, with many different 'issues', but cloudy water hasn't been one of them. And the oily film on the surface is a puzzle too. Heck, when I was new to the hobby, cycling was something that involved two wheels and pedals.

Back to the OP, if you have a QT or hospital tank, I'd be moving the survivors in there until the other issues are resolved. It seems like of a case of one fish dying, and that fact being missed. Then the snowball efect takes over and .......

[NanoSF]

Is this the first time you did a gravel vacuum? There are different opinions on this, but I say the in between opinion is best. If you gravel vacuum only brush the surface of the gravel. Especially early on in the tanks life. If you shove the vacuum to the bottom all over the tank is is going to stir up all kinds of pockets of trapped bad stuff. I wonder if that is what happened here. BTW the other opinions are, don't do it at all, do it in sections, or do it to the bottom all over the tank. I say the only other option is do it in sections, one small section each water change. I think people get caught up in cleaning the tank as much as possible when they have a new tank. When often it is best to leave tanks alone more.

The oil is normal IMO. It depends on what you call oil. A bit of rainbow discolour and some surface gunk is normal if you don't have and kind of overflow. Especially with fish dying. They could have released some mucuses or something that is sitting at the surface.

Even if a cycle is done that does not mean it is stable or strong. If you cycled with basically nothing in the tank and then have since added this many fish (6 that died, and some that are still alive) you may not have a system that can maintain the waste yet. Couple this with changing a filter and stirring up gravel, the beneficial bacteria just don't stand a chance.

IMO the suggestions to get through this are all good, but the problem still exists in the future if you are not careful. Add fish slowly, feed as little as possible at first, and don't clean the tank much other than water changes. If you change the carbon in the canister don't touch anything else. Like a previous post said, do changes at different times. When you change carbon don't clean the canister, or take out any filter floss/mesh filters.

Good luck with it.

[washefuzzy]

If you are just rinising out the filter median do so in water from the fish tank. Tap water will kill off
the good bacteria. When changing filter median only change half of the filter median at a time. Therefore you will always have good bacteria in the water. I change the floss in my filters once a month and rinse out the sponge in tank water. Sponges last forever. Well at least six months. If I change the sponge I don't change the floss at the same time.

When I had an ammonia spike several of my fish died and the water became cloudy. If it is a ammonia spike it not necessary to quarantine your fish. Just do water changes like said previously.

[sas]

If I'm not mistaken, Cora is a seasoned fish keeper .
In which case I'd be more inclined to be looking at a contaminant
issue, although changing filters out after only approximately two
months could be the problem as well.


Welcome back , sorry to hear that you're having a problem.

[NanoSF]

Ya it's hard to know if you are belittling people when you give basic advice, but you also don't want to avoid the obvious in case that is the reason for problems. Sorry if I sounded like I was suggesting you are a rookie.

[Saltcreep]

Ya it's hard to know if you are belittling people when you give basic advice, but you also don't want to avoid the obvious in case that is the reason for problems. Sorry if I sounded like I was suggesting you are a rookie.

Me too.

[sas]

Absolutely, you guys are spot on.

My apologies for how my post came across, I'm was just very happy
to see some previous longtime contributors coming back.

[Saltcreep]

Absolutely, you guys are spot on.

My apologies for how my post came across, I'm was just very happy
to see some previous longtime contributors coming back.

No apology necessary, I don't think. Your comment is as 'spot on' as some of the replies. What it really highlights, is the problem we all have from time to time replying to posts when we have limited information or knowledge of the situation we're commenting on, or of the experience level of the person making the post. More info is always better.

Now, back to our regularly scheduled program - Cora, how is the tank doing?

[cora]

Thanks for the welcome back sas!

And I appreciate everyone's advice!

As for the tank.. well I am pretty sure I didnt over gravel vac it. I am generally a fan of less is better. I didnt rinse out the sponges, just changed the carbon portion of the filter. I have not lost any more fish, but another one is showing signs of what looks like fin rot? the water is still the same opaque colour, and still seems oily on top, I did change out some of the water just in case it was ammonia, but at the moment the fish aren't showing signs of ammonia poisoning. I am considering adding some melafix to help with the fin rot, except I am warry about what might be causing the problem, I do not want anything to react and make it worse.. like too much in the tank. Anyone have any thoughts?

While the tank has only been running 3 months, the fish I have had for more than 6 months, so they were established and very healthy.

[sas]

I'm of the school of just keeping the water at it's highest quality when I have
any kind of fungal infection. Lots of water changes, carefully done.

I've killed more than enough fish by adding medications, but maybe
that's just me. The only thing I add now to a tank is salt and only if
I'm really pushed.

[Dekker500]

As a suggestion for getting rid of the surface problem:

Since I have little to no surface agitation on my tank, I too used to notice an unsightly accumulation of 'stuff' on the surface (oils?, eventually scum). Then about 7-8 years ago I bought a Fluval/AquaClear surface skimmer.

With the skimmer, my surface is crystal clear. If I don't use it for a week or so, my surface is 'crowded'.

As sold, the product is "OK" but to make it maintenance-free, you just need to make a donut out of rigid foam (such as styrofoam, or hard pink insulation, etc) to fit under the floating rim. The original design relies on a pocket of air to keep the top floating, but rowdy fish can disrupt the bubble, and the float will sink (rendering it ineffective). The foam removes the need for this air pocket, and the float will never sink (unless your lower filter intake is clogged).

[washefuzzy]

Cora I just figured out who you are by the avatar. Welcome back. If I had know it was you I wouldn't have given information for a nubby. 

[Nerine]

welcome back!

hoping your fish are doing better...frustrating to say for sure

[cora]

Update- almost everyone is looking better except the one with tail problems. the tank still looks funny, but I am happy with the way the fish are looking. I think just time will do.

[cora]

well almost a week has past, and I have lost everything except my two pearl Gourami. The last 3 barbs where dead when I got home from work today. I did a 5 in 1 test strip when I got home, and everything looks normal, the water still looks funny but less so than it did. So I just dont know, It really has me confused.
Gonna keep my fingers crossed for the last two.

[Fortix]

I had the "oily" look in my blue lobster tank for I dunno how long.  Then I noticed little baby lobsters and no more oily look.  Might just be a coincidence, but it took over a month before it cleared on its own.