Please help all my tropical fish are dying

[Arkmind]

My tank is in serious trouble. It is a 50 gallon tank with one of those external filters....The filter is like about a foot tall cylinder with some fibris mats and some plastic cylinder like material in between the lairs. There is also a foot long bubbler stick in the bottom of the tank that runs around the clock as well and the water temperature is a constant 77-78 degrees 24 hours a day. The tank has been going for about 4-5 months now everything was going good....there was only maybe 8-9 small fish in it and a bunch of small weird snails that hitch hiked a ride on a live plant an started breeding. Fast forward to today now in the last 2 weeks alot of the snails are dead as well as all the fish but 2 of the same species. I am sorry I do not know the species it is a neon yellow fish with a tiny red spot on it's forhead. An now even one of these fish is now looking not very well and is swimming sideways and at times it seems like he is gasping for air although he is doing it while underwater. He seems to get around pretty well albeit swimming sideways the other fish seems to be fine atm. I do not know what is wrong the only thing I have atm that I can use to test the water is a PH strip which came up as 6.8. I feel really bad and I wan't do help this fish and not lose these last two and get the tank back in order and I feel really bad that I neglected it and let all the fish die. Any idea what is going on here? Other then the fish swimming sideways I can't see anything physically wrong with it. I have not cleaned the filter at all as my brother has had fish for many years and I asked him if the filter needs to be cleaned and he keeps telling me no.

[fishmommie]

Without knowing your water maintenance routine, it's difficult to tell but I would guess your fish have ammonia or nitrite poisoning. Do an immediate water change. 75% would be good.
Tomorrow, buy an API master liquid water test kit and check ammonia, nitrites and nitrates.
If either the ammonia and or the nitrites are above .50 then you have your answer as I suggested above. Do another water change and keep doing them until both are below .50.

[Arkmind]

Without knowing your water maintenance routine, it's difficult to tell but I would guess your fish have ammonia or nitrite poisoning. Do an immediate water change. 75% would be good.
Tomorrow, buy an API master liquid water test kit and check ammonia, nitrites and nitrates.
If either the ammonia and or the nitrites are above .50 then you have your answer as I suggested above. Do another water change and keep doing them until both are below .50.

To be honest the only thing I really did was add water when it got a little low. I never emptied and refilled it or anything like that.....and I have never cleaned the filter since I first set it up 4-5 months ago. Does this info help with your diagnosis. I will go to the store when it opens tomorrow and get the testing kit.

[talldutchie]

And you didn't change water because? A 30% water change now with water you've treated with a conditioner against chlorine is a good idea.

Not cleaning the filter isn't necessarily a bad thing. Cleaning it without knowing what you're doing makes things worse.

[Arkmind]

And you didn't change water because? A 30% water change now with water you've treated with a conditioner against chlorine is a good idea.

Not cleaning the filter isn't necessarily a bad thing. Cleaning it without knowing what you're doing makes things worse.

I have well water so there is no chlorine in my water I commenced with the water change I took about 60 percent of the water out and refilled it with clean tap water. I think I may have been way over feeding as there was quite a lot of debris on the bottom gravel that was kicked up upon refilling the tank. I hope it settles soon as now my poor fish are swimming in a cloud of muck. I never changed the water cause I didn't know it was supposed to be changed.

[talldutchie]

I keep forgetting, not everyone believes in being prepared when keeping pets.

OK, next top tip, find a piece of hose somewhere, I use 6mm hose but in your state anything will do, and start syphoning that muck from the bottom once it's settled.

[mommy1]

I keep forgetting, not everyone believes in being prepared when keeping pets.

Not all pets, just fish.. ok guilt trip over.
The tank is probably cycled because you never did any filter maintenance. Because you never took water out or cleaned the gravel, the the nitrates and dissolved solids in the water are probably at toxic levels and that is probably what is killing your fish. As talldutchie says, get something to siphon the gunk out of the bottom of the tank and start doing water changes. You will also need to clean the filter media in clean water, because you have well water you don't have to worry about the dechlorinater, and put it back in the filter.

[talldutchie]

That filter can wait a few days more. Let's get the worst of the bottom first

[Lady Hobbs]

Agree with mommy1. Fish need clean, fresh water changes. Most of us change water weekly, for me 50%. Water is replaced in the wild by water moving in and moving out and rains. You can not expect fish to live for long in a closed up system that never gets changed or cleaned. I expect that your nitrates are sky high. Your pH is fine tho. Replacing the filter media will set the cycle back but rinsing it out regularly in tank water you are tossing out will not.....or in a pail of dechlorinatored water. You do not mention what filter you have but often on larger tanks, two filters are used so one can be cleaned and then a couple weeks later, the other.

[fishmommie]

Now that I know you have never made a water change, I agree with the above posters. Your tank is most likely cycled and your problem is from the poor water quality.
When you get your API liquid test kit also pick up a gravel siphon. You can use it to change your water and to clean all the waste from the bottom of the tank. What you are stirring up is not just food, it's fish poo.
Once you get all of the waste vacced out, and start a regular weekly water change regiment, you should see much improvement in your fish health.
Good luck and I would advise reading the free e-book here on the forum. It will give you many insights on fishkeeping that will benefit you and your fish.
Good luck.