katie1022

Hello,

I have a fish tank that has been set up since August 2007. I had 2 bala sharks, 2 Mollys, and an Angel fish. 10 days ago, in a effort to keep the gravel cleaner, I installed an Undertow gravel filter in addition to my regular Whisper filter. While I was at the pet store I picked up two new fish - a plica and an upsidedown catfish.

The water initially looked very clean, but over the past week became somewhat cloudy. On Tuesday morning I noticed that one of the bala sharks look very sick and lethargic. Over the past 36 hours ALL of the fish have died. I am so upset! I am new to the fish world had not been keeping track of ammonia and pH levels so I cannot report these numbers. The most likely explaination seems that the 2 new fish brough some kind of infectious disease to the tank, although it took over a week after the introduction of the new fish for signs of illness to develop. I am wondering if the addition of the second filter could have somehow disrupted a balance in the tank. Is it possible that the water was overly aerated/filtrated?

I would greatly appreciate any insights or advice anyone has about this. I want to make sure that the problem is completely addressed before I attempt to restart the tank with new fish.

Thanks,
Katie

susitna-flower

FIRST, KATIE - LET ME SAY WELCOME TO FISHLORE!

Sorry about your fish losses.......everyone here has been new to fish keeping at some point, and we all understand there is a learning curve that can be a bit rough.

Sounds like your tank was very overcrowded....the rule of thumb for stocking a tank is 1" of ADULT fish size per gallon. That is not the size you buy them, but the size they will grow into....

This rule is so the tank has enough room for the fish as they grow, but more importantly that the bacteria increases, as the fish grows and produces more waste, so the bacteria can keep up with the conversion of toxic ammonia and nitrite into nitrate. In other wise the nitrogen cycle.

You said in your aquarium profile that you didn't know about the nitrogen cycle. If you will go up to the top of the page and open up the heading "ARTICLES", go to the link on the nitrogen cycle, and read this thoroughly before you try to restart your tank.

The fish you had in your tank would be counted at about 56 inches. All this in a 15 gallon tank, even if they weren't full grown yet were producing much more waste than that size tank could handle. Next time research each fish before you buy it. For this tank you can keep a very small school of 2" fish like cardinal tetras and maybe a bristlenose pleco.

If you want to keep larger fish like bala sharks (they need a tank at least 72" long) you will need a 125 gallon tank.

Once you have decided just how you want to proceed, I am sure you will get lots of further advice and help in setting up your tank to be healthy and a lot more fun.......Good Luck and keep posting, let us know how it goes.....

kra-z-fishmumm

Sorry about all your fish. Your next big purchase needs to be an API master tester (approx. $35) for testing your pH, ammonia, nitrates, nitrites. Check your water and then go from there. Let us know what the results are and we can help more. Again,,, sorry for your loss

COBettaCouple

Hey Katie - Welcome to FishLore! :;hg

We're sorry that you lost your fish but what happened was probably a combination of
the ugf and when you added the Pleco (55-75g for one of those is minimum) and upside down cat it was too much for the bacteria in the tank and the water toxins went through the roof.

I'd recommend getting the API master freshwater kit and Prime (tap water conditioner) for your tank. You can clean the tank out and cycle it fishless using flakes and testing with the kit to determine when the tank is cycled.

For fish, in a 15g you'll want fish that grow to 3" or so (adult size) tops and at most a combination of 15".

capekate

Hello Katie
and welcome to fishlore! I agree with all the advise above. Also wanted to add, that it is very possible as well that the two new fish you brought into the tank were sick or at least one of them, and caused the deaths of your fish. It is so important to quarantine your fish when you buy them before adding them to the tank. There is no telling what disease they may be carrying from the LFS. Most of us have at one time or another introduced fish this way and ended up with fish loss before learning about quarantine tanks. I know that I have been guilty of this as well.
There is a lot of information on this site that will help you re establish your tank and get it ready for new fish. Good luck with it...

~ kate