Help! I don't want my whole tank to die!

[alimcgehee]

I have an established 45G freshwater w/ 3 Mollies & 2 Dwarf Gourami. I also have an aquatic terrarium with a River Cooter hatchling.

Everything has been perfect, until I go out of town this week, and my brilliant fiance & his best friend decide to pick up a couple of minnows from a local bait shop as food for the Cooter. You guessed it, three non-quarantined minnows hung out in my tank for almost two days before I found out. Told them to get rid of the minnows immediately, and keep an eye on the rest of my fish.

Three days later (last night), I get home & inspect the tank. Found my lyretail Molly dead at the bottom, no telling for how long but fuzz had started to grow. My Dalmation Molly has gone from black & white mottled to almost completely black. Found two with nipped fins. The more docile Gourami isn't acting erratic, but his color isn't looking too great. I immediately disposed of the dead fish, and did a 50% water change & changed both filters.

This morning, the fish seem wayyy less stressed (except for the calm Gourami) & are eating like normal. Water test results:

0 Nitrites (normal)
under 5.0 ppm Nitrates (normal)
between .25 & .5 ppm Ammonia (my tank is usually 0)
pH 6.5 (much lower than normal, usually 7.0 on the nose)

What do I do at this point? Just wait & hope for the best? Any advice would be greatly appreciated.

 

[rugrat]

sorry no one has answered this, I was curious too. I think the answer is hope for the best :/

I would do another water change the next day, not 50% but 5 or 10% every day till the ammonia drops down. Sometimes when something "big" happens to my tank and the fish are stressing I shut the lights off and they seem to do better.

 

[OrangeCones]

Did you really change the filters? The filter's media is what houses your beneficial bacteria and should never be changed, just rinsed in change-out water.

I would continue to do 25% water changes daily until your ammonia and nitrite remain at zero. You may expect to see some spikes if you did indeed change all filter media.

 

[alimcgehee]

Yes, I changed the filters. I found fuzz/mold from the dead fish caught in it, figured it was the best thing. Found Molly #2 dead tonight after getting home from work. Just did another 25% water change. Will test tomorrow before work. Completely bummed.

 

[OrangeCones]

Unless the filter's media is completely disintegrating, you should not change them. Just rinse them out in the change-out water.

You will now need to recycle your tank since you no longer have much of the beneficial bacteria in the tank. Some still exist in the hard surfaces, but most were contained in the filter's media.

If your other set up has a filter running in it and hasn't been changed (not sure what a 'cooter' is), you could rinse that filter's media into your other tank to help restart the process.

In the meantime, continue to do water changes, and make sure the new water is dechlorinated and the same temperature as the tank's water since sudden changes can shock fish, especially those struggling to recover from the fiasco of your 'brilliant' tank-sitters!