What's the biggest mistake you've ever made?

when i had my first tank (not bowl) i was about 10. i religiously cleaned out the tank every single week

i would scrub it down and give it a really good clean with fairy washing liquid and rinse out all the gravel every week, i even cleaned out my carbon bubble filter

man, the tank sparkled after i cleaned it, crystal clear water no probs

i couldnt work out how kept losing fish......
 
I have made sooo many mistakes however, since you restricted the reply to aquaria:

Years ago I had a 100 gallon in my office. I housed 3 oscars and 2 alligator gars. One evening I came into the office to find a strange aroma. The fish had been in a fight (never did determine which) and cracked the glass tube on the heater. Tis caused it to allow water in and shorted the heater in the on position. The water was boiling the fish. I went to reach in the tank to remove the heater when I realized it could cook me also. Needless to say it took a number of hours to clean the mess and vent the office. I am glad no one else was there to be a not very friendly neighbor. Since that night I do not keep large predators. Much easier than taking steps to safeguard everything.

Charlie
 
My worst were when I first started years ago. I would skip water changes and completely clean filter media in the tap. I had an Oscar in a 30 gallon whom I fed feeders. I couldn't understand why he kept getting diseases. ( he's 8 now and lives in a pond ), I had South Americans with Africans. I didn't use conditioner. Basically, I didn't research.
My worst blunder lately was draining my sump to clean it and forgot to turn the heater off. Kablooey! Glass everywhere. Now everything's hooked up on the same switch, so it all goes off except the lights. And I have a plastic heater.
 
with fairy washing liquid
Is it used for washing a fairy or for a fairy to wash something else with?

:lol:

Bringing home animals (turtles) before having tanks ready to go for them, and THEN doing the research and THEN finding out how big of a tank I needed and how much filters would cost.....
 
I guess I have 3. The first was getting a betta for a 1g hex, moving it off the coffee table to clean and putting it on the counter in front of the window then forgetting to move it back to the coffee table. Next day I came home from work to find, basically, a boiled betta.

The second was not so bad. After about 6 months and learning from my mistakes with the bettas (3 dead bettas in 2 months from little stupid beginner's mistakes) and actually doing research, I had a figure 8 puffer and 8 bumble bee gobies in a 44g corner. I was doing a water change with the buckets and siphon. Fortunately, all my fish (at the time) avoid the tube, and I got distracted doing other things while waiting for the bucket to fill up. Came back a few minutes later to find the bucket over flowing on our carpeted living room floor! Fortunately, it was not long after it filled up, so there was probably only a gallon or two in the carpet.

And lastly, after getting so excited about fishkeeping and actually doing research and having no losses in months, I was chatting with my mom about how great fish are. She went out and got another 1g hex and put, any guesses? Yep, a calico fantail goldfish! After explaining that goldfish need at least 30 gallons, and preferably more like 55, she smiled and said, "Oh, it'll be fine!" :wall:

I think she's gone through at least 2 goldies and has a betta in perhaps a 1 liter vase with a plant (at least I got it through her head that they need surface air to breathe) and another in maybe 1/2 gallon with another plant. She claims the one is over a year old (in her care) and I don't see any fin rot, miraculously. I doubt that she does many water changes. Oh, and my aunt-in-law had a betta in one of those tiny biorb things that is maybe 3 inches in diameter and has maybe a half liter of water in it. She finally moved it to a bowel with more like 1-1/2 liters in it and a water lettuce. Can't teach them anything either! I've offered my 2.5g so many times, I've lost count. No filters, no heaters, probably no water changes. ARRRGH!
 
when i had my first tank (not bowl) i was about 10. i religiously cleaned out the tank every single week

i would scrub it down and give it a really good clean with fairy washing liquid and rinse out all the gravel every week, i even cleaned out my carbon bubble filter

man, the tank sparkled after i cleaned it, crystal clear water no probs

i couldnt work out how kept losing fish......



I use to do the same thing when I was 15, thats how my parents told to clean the tank if I was going to keep one. I had a betta, and a red fin shark in a 10g. Think about that a lot, since I couldnt keep anything in there besides the two, which I am surprised they lived.
 
Okay, this is something I cried over for sometime. I was doing a water change in my tyger shrimp tank. Apparently I had poured the water in too fast, and the distilled water gallons who had been sitting inside for days were still too cold. They all looked okay when I poured the water in, but that was because they were in shock. I killed half my population that day. It is a 18g hex, so when you pour the water in, the dispursement is strange and instant on the entire tank.

Another time, I was spraying for fleas, and some of the myst had gotten into my CBS tank. Well, I lost 11, only 1 survived. She is now in with my bumblebees, I got them when they were babies, watched them finally grow up to have a batch of eggs 5 months later, and then they die. Some of the poison had gotten into my Yellow shrimp tank too, lost about 15 of them. And all the females dropped their eggs:( I have plastic sheets now to cover the tanks when I spray chemicals inside.
 
I trusted the people at petsmart, and bought 2 oscars, 1 dempsey, and 4 common plecos for a 20g.
I went back the next day and returned all of them.
 
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