so i got this fish tank beginning of the year because i wanted to have some fish. nothing fancy, just a couple goldfish. i got everything and then let it filter through for a week before i put some fish in. i got three different kinds of goldfish. only about 2 weeks later, one died and i took it back to the store to have the water tested and some of the levels were really high which i then fixed and the other two were fine. few months after that another one died. (mind you we were having really hot weather at the time). so i just had one while it cooled down and then once it wasn't so hot i got another, just an orange fantail. they both got along pretty well so i went and got another, back to three like i had originally. they were all fine together for a month or so before it's all turned to shit again.

one of the original three (klaus) wasn't moving as much. once i had a good look at him i noticed that his tail/fins were doing that tearing thing (fin rot) at which i got some solution to put in the water to help. unfortunately it was just getting worse very quickly and by that same night he was gone. the other two (deucalion the fantail and hannah the other goldfish) were completely fine and i read that it wasn't contagious or anything. i did a big clean of the tank and everything in it, treated it and put the fish back in.

just this week deucalion had just been sitting in the corner of the tank, not really doing much but other than that he looked fine. yesterday or the day before he'd been getting the tearing/shredding like klaus had. i started treating it like i had before and i'd only just cleaned the tank (which i do at least once a week, siphon the gravel + clean the plants + change the water and sometimes clean the filter if i need to). i treat the water every couple of days just to keep it at the right levels. anyway deucalion passed while i was out this morning and now it's just hannah and idk what it is that is making them get so sick? it's making me feel really bad that i'm not taking care of them right even though i'm doing everything i can and am supposed to. i've only had this tank since january and i've already gone through four fish :/

if hannah goes i'm not sure i even want to continue with fish after how much of a hassle it is just to keep them alive. so i was thinking maybe an axolotl, since i spent quite a bit on the tank and i'd still like to have it. i've been reading up on them and how to take care of them but it doesn't really say if they're any easier to care for or not compared to fish or if there's anything else i can do to ensure that my fish won't keep dying. or if there's anything else i can put in the tank.

How big is your tank? A single goldfish needs 30 gallons and you need 10 gallons for each additional goldfish, so for the three goldfish you would be needing 50 gallons. If you get any that grow bigger than 8" then you'll be wanting a 100 gallon tank. Also, cleaning the tank once a week isn't enough. You need to be doing it daily, or at least every other day, doing 50% water changes. What kind of filter do you have? You may want to look into getting a better one. Before you get any new fish, take out your current fish, cycle the tank and then test it twice a day (once in the morning and once at night) until it becomes balanced. Then get your fish, continue the testing and then you can do the cleaning/water change weekly.

Make sure you're feeding them enough, not too much. They feast for 3 minutes twice a day, so if they're not finishing the food then you're giving them too much and that will just be waste.

Goldfish are very messy and if this is too much work for you then I suggest looking into getting a different fish. Or, yeah, an axolotl would be easier to care for. You'll want to get 2 of them if you do so it doesn't get lonely :P

Please don't listen to that 30+ gallon thing, no offense to but those numbers are crazy high, where did you get those hun? If 1 goldfish needs 30 gallons, then EACH fish would require 30 gallons of space, resulting in a 90 gallon tank. Uness her fish are more than 4" she doesn't need that kind of space, I've had goldfish in tanks around 30 gallons and they've done wonderfully in them. I'd say it's more like 1 fish per 10 gallons, not 30 for a fish and then 10 for the other 2 fish, that's just weird math to me.

Water changes every other day is a very drastic change and will cause more harm to the fish than good- 50% water changes are usually for salt water in dire situations (such as high nitrates/nitrites, too much calcium/alk/mag/etc.)

A week usually isn't long enough to cycle a tank. How did you start its cycle off?

Most tanks will take a good 2+ weeks to get a steady amount of good bacteria built up (feed the tank like you would feed a fish, just without the fish, this starts off the cycle). That way when you start adding fish they have something thats "set up" for them.

Gold fish while "easy" are still handled in rough ways and not always in the greatest tanks at pet stores, goldfish are the "dime a dozen" feeder fish and even if they are super pretty most pet shops won't take much care of them which could lead to many internal/external problems. Goldfish are typically very "dirty" fish too as they are constantly pooping, and poop turns to nitrites, which turns to nitrates, which too much will cause illness and eventual death in fishies :( nitrites are TOXIC to the extreme... if these are teh levels you're testing and they are showing high, don't add anything until you get them under control, thats when you begin water changing. Also, please use liquid test kits- NOT the strips. Strips are NOT accurate.

Lets talk about your tank- What size is it and what kind of filter do you have? I always suggest using a filter 2Xs the rating of your tank size, so if you have a 30g tank, get a Pengiun HOB filter rated for 60+ gallons (I believe the ones they sell that are the size up are a 75gallon) and they run about $30. Totally worth it. Don't use under gravel filters as they collect too much waste and create pockets of nitrates that you release when vaccuming the gravel. They are a wonderful system and have a biowheel in them to help regulate some of the natural occuring bacterias in the tank (do NOT wash this off). Cleanign out the filter is good but if you do it too much it takes out good bacterias that the fish need.

Feeding the fish is something I feel people really "over-do". the whole "FISH WILL EAT FOR 3 MINUTES" thing is faulty. Fish will eat and eat and eat and eat. Gold fish will eat until they burst and still try to eat, they are just that way. I feed a few amount of flakes/pellet mixed and let them eat that first, then give them a bit more. Don't let them gouge themselves for 3 minutes, thats a TON of poop thats gonna be added to the tank and they really don't eat that much. Plus, here's a fun fact; Goldfish DON'T have stomachs!! Their intestines run all the functions a stomach would and that is why they poop so fast after/while eating, because they are missing a step.

Weekly water changes of 20% of your water volume is okay, but stay away from things more than that unless you have a major problem.

I hope this is easy to understand, I've been working at an aquarium since 2003 and help run a fish farm (where we have goldfish, carp, bass, and sturgeon) so I have tons of experience setting these things up, I've got about 5 fw tanks going and 3 salt atm :) If you need any help please message me!

yeah i was looking at the conversions (we use litres here) and it said that was like upwards of 100L and it didn't seem right. thanks anyway for the help !!

i'm pretty sure my tank is 20L and the store i got everything from is really big on fish, they have a lot of tanks and seem to know their stuff. or so i was led to believe anyway. the first first that died was because of the nitrate/nitrite levels but when i test them now they're at 0 and have been for a solid few months. not sure about what filter is it but i have this tank: here. but i'm open to buying another filter if there's anything better i can put in there. the filter i have has uh the bioballs in them and i only wash the sponge thing maybe once a month. if i don't use the gravel siphon is there anything better i should use? or should i just use it to take the water out and then clean the gravel by hand? or how often should i be cleaning the tank?

i can't remember if it was a week or 2 weeks (i think it might have been 2 weeks) and during that time i was treating the water and putting a little bit of food in there just to get the cycle started. i made them test the water before i decided to get any fish and they said it was fine. but yeah, my mum made a comment about the fact you don't really know how old a fish is or what sort of environment they've been in prior to purchasing them.

i'm definitely just going to keep hannah for a while on her own to see how this goes, if not i might start again with the tank and go from there. thanks so much for the help! ;u; do you mind if i friend you so i can bother you with my fish questions when i need to?

20 liters is 5 gallons... You only have a 5 gallon tank?! One tiny goldfish requires at least 10 gallons (38 liters). If you want to know where I'm getting those numbers, seriously, just look up any basic care guidelines for a goldfish. Combine that tiny space with some messy fish and no wonder your water quality isn't any good.

You obviously do have a major problem and that is why I suggested doing a higher percentage water change.

Sorry you're getting drastically different answers here, but good luck doing whichever you choose.