I have an aquarium that was home to 14 fish, until about 4 days ago when I realized one of my fish went missing. I’ve looked all around the tank; it’s not floating on the top, it’s not hiding in the rocks or the plants. I can’t find it. I’m going to assume it’s dead because I watch my fish closely, and I haven’t seen this one for a while.
My question is, just how bad is it for this (presumably dead) fish to remain in the tank (assuming another fish didn’t eat it, something I don’t believe happened)? I’m hesitant to empty the tank because I will then risk death to the rest of my pets, and I don’t really want that.
Did you check the filter(s) carefully? I’d say let your nose be your guide. A balanced aquarium has a pleasant smell. If you start to smell the unmistakable odor of putrification, then you need to act fast as your water quality will go down fast. You should also check carefully all around outside the aquarium. Fish seem to have an uncanny ability to find any opening that leads to the outside and jump out.
If the worst case scenario happens, be ready for it. Have the largest container you can find/afford standing by so that when you take out your fish, you take out at least half the water in the tank along with them. You should have a spare heater on hand to use (I once had my heater fail at 9:00 pm in freezing weather where it simply wasn’t possible to keep the whole house at tropical fish temperatures and the only thing that saved my tank was a spare heater) and a spare filter. All heaters and all filters eventually fail. Be preparred! Once your fish are safe in their temporary home, dump the rest of the old water and thoroughly wash the rocks, sand, and whatever and look for the dead guy.
If at all possible, you don’t want to clean the filter at the same time you clean the tank so drain all the water out of the filter and give it the smell test. Look carefully inside for the dead guy and take the filter media out and look through it if necessary. If it smells bad and you feel there is no choice, then change the filter media or wash it but this will destroy most or all of the good bacteria so try to avoid it.
When you’re ready to reinstall everything, put it all back in the tank and let it sit for a while before adding water and then give it the nose test again. If everything smells right, fill the tank half to 3/4 full, condition the water, wait for the temperature to stabilize and then add the fish back with enough of their water to fill the tank. The water should have enough bacteria in it to restart your nitrogen cycle but the best bet would be to run your spare filter for a few days ahead of time in the main tank for it to get a good colony going and then use the spare when you restart the main tank. Cut back on your feeding somewhat for the first few days at least. Stressed fish eat less and you don’t want to overload the tank with waste.
How big of fish and tank are we talking about here? A guppy in a 100 gallon tank isn’t much of a worry IMO.
If the fish is gone I would chalk it up to a jumper or a sinker/dinner for the others. Watch your Ph and other levels and if they remain stable I wouldn’t sweat it much.
You might want to do a partial water change in any case.
What kind of fish? Guppies are meat eaters and WILL eat other fish. I had a dozen Guppies in a 20 gal tank. I noticed a dead (sinker) Guppy one day before going to work. When I came home to remove the body it was completely gone. I figure the other fish and my snails took care of it.
To be sure though do a 20% water change, check your levels and filter. 1 Guppy in a 20 gal tank did not make any dent in any of my levels.
I have a channel cat in my tank and he makes fast work of any dead fish…sometimes he doesn’t even wait til they’re dead. You don’t have to have a piranha to have a fish eaten. Fish eat fish.
My opinion is to check for a jumper, like the other’s said. If no luck there, vacuum the gravel to collect the remains.
I had a fish disappear once. A fancy bubble-eyed goldfish. A day later, I noticed a ceramic decoration had been tipped over and my missing fish had somehow wiggled up inside. (I never would have figured he would have fit) So examine all your decorations really carefully. In my case, the fish was still alive and I had to bust the ceramic thing open with a hammer ot get him out. He lost a chunk o’tail and was probably traumatized but he survived…
Is it a freshwater or saltwater aquariums? size? don’t rule out jumping out of the tank, you wouldn’t neccessarily smell the dead fish if it’s small. also, if you don’t know when it disappeared precisely, it migh have decayed or been eaten. many saltwater aquariums have shrimp that will happily eat dead fish. in fresh water many types of fish will eaten one of their dead brethren, and you won’t find the skeleton.
If the fish is wedged somewhere and uneaten, worst case scenario is you get an ammonia spike until your denitrifying bacteria keep up. Not a big deal, since it’s easy to fix. Do a few extra partial water changes and if you don’t have water testing equipment, go down to your local pet store and have them test for you to insure your tank is balanced, a lot of stores will test free of charge.
It’s 29 gallon, freshwater tank. I still haven’t found it, but I tested everything and it’s all okay. I’ll vacuum the gravel tomorrow when I have help, but I’ll be sure to keep an eye on the ammonia levels (already had one of those disasters with this tank, lost 3 of my fish) and whatnot until then. I only had 2 of these fish, and I think the other one’s depressed (no, seriously). Poor guy…
It’s my first tank, and I’ve never had a fish just disappear before. Thanks for the tips.
We’ve had fish disappear, too. A friend of mine, highly experienced in aquariums, says that the algae eaters may eat a dead fish on occasion. We have the larger of the two types of algae eaters. I forget their names, but they are large guys, not the ones as thin as a stick (which I believe are the Chinese algae eaters). We have two of them in a 40 gal tank.
Don’t forget to mention the smell when they die. Boy howdy. If you ever have a dead pleco, put it in a baggie BEFORE you take it out of the water, or you’ll be cleaning up vomit from your floor.
I had a Plecostomus that dissapeared one day. I assumed it had either flung itself from the tank (like a chinese algae eater once did to me) or it had died and been consumed by the other fish in the tank. Upon breaking down the tank 18 months later, I discovered it had somehow managed to swim down the aeration tube and get beneath the under gravel filtration. I seemed perfectly happy and healthy, and had almost doubled in size. It was actually large enough where I’m not certain that it would have had room to turn around anymore.
Assuming it’s not, I’ve had a series of plcos in my time, and none of them have grown bigger than the tank could accomodate - I was always led to believe that “grow to the size of the tank” deal was an old wives tale, but none of my plcos have gotten bigger than about 16 inches in lenght. FWIW, I’ve seen some 3 footers in large aquariums and such (like at the zoo).
Anyhow - you house them just like any other large fish - assuming there’s not a punchline coming here… I was trying to think of one, but nothing is sprining to mind.
No punch line. I was given two when it was discovered that I had Killies at work. They are with the Beta I rescued from a flower arrangement in a ten with a couple of flower pots to hide in. When I get near to the tank they move about violently. I don’t what to buy a fifty just for these guys, but they need larger accomodations. Like the Amazon river.
