Last fish died, now what

Factual Questions
1

We have a 30-35 gallon tank, freshwater. We had neon type fishies in there. They’re all gone now.
My boyfriend wants to start with goldfish but apparently the tank isn’t ready for that.
So, what is the best way to thoroughly clean the tank?

What needs to be thrown out (castle, stones, thermometer, heater, filter).

After the tank is all clean and ready to go, how many goldfish should we get to start out?

How long do we wait before adding more?

How many goldfiishies can we put in a tank this size?

Thanks!

2

Use bleach water in the tank and whatever materials you keep in it with the circulating pumps running. Drain and rinse the tank until dissolved sludge is removed and tank is clean. Fill the tank. Let it sit a few days with the circulation system running before you use it for fish. Any live plants or fish will of course be killed in bleach water.

3

Keep in mind that goldfish can grow quite large depending on the size of their environment. As a child, I had two goldfish in a gallon size fish bowl for about 2 years and they grew in length to about 1 1/2". They were placed into a 20 gal fish tank and within about a year they tripled in size.

I add about 6 to 8 goldfish to your tank and wait about a year before they’re ready to eat!

Yum!

4

Not many. One. Two. I think the formula is one GF per 20 gallons? Goldfish are enormously messy and grow quite handily. They really don’t make good tank specimens. Seriously. That’s why they should be in ponds. They also might live much longer than you want.

I’d recommend rebuilding a nice community. A school of 15 mid column swimmers, and a few other colorful individuals for interest. Have fun!

5

Drain it. Rinse out the substrate with clean water. Why would you throw anything out? (OK throw out the castle, LOL). I would not use BLEACH or soap ((((shudders)))). Say what?

If you don’t know about the nitrification cycle, you need to do some reading. It sounds like maybe you don’t. Bleach will kill the tank, exactly what you don’t want to do. You need to re-establish the nitrification cycle in this tank. There are many ways of doing this. Check out some aquarium bulletin boards for help.

Tanks take some time to build. Don’t try to do it overnight, gradual is the key. My last 80-gallon took a year to fully populate.

6

If it is slimy, I’d empty in the backyard, and scrub it all out with a CLEAN NEVER EVER USED scrub pad and salt. Salt makes a great scrubbing agent that is compatible with fish. Again, don’t use soap!

7

Thats what I was thinking - unless you have some sort of active fish-killing infection going on in there, there’s no need to bleach the tank.

Assuming you DON’T - get a clean toothbrush and clean any algae build up off your toys (castle, heater, etc) as well as the sides of the tank. Use a tank vac to clean your gravel. Replace the media in your filter that needs to be replaced or possibly look at getting a bigger filter (depending on what you have). As other posters have said, goldfish tend to be messy and you can increase the number you can have by increasing the efficacy of your filter.

If you go that route (i.e. new filter), get a water testing kit at the same time as your new filter (they’re not expensive) so you can keep an eye on the water quality.

I would then start with 2 or 3 new goldfish (depending on their size) moving up to as many as 6 or 7 (again, depending on size). If you go for fancies, they will not get as large as some others, but are more particular about water quality and temperature (again - better filter is needed!).

If you DO have some sort of active infection - well, bleach the crap out of everything, rinse well and start from scratch. (Boiling water is effective too).

8

By goldfish, I assume it is meant ‘pond comets’ or the smaller non-fancy type (~similar to koi, but a dime-a-dozen variety). This type is fairly tolerant of ‘dirty’ water, and grows fairly fast in mass/waste production.

Usually, you should keep it to around 1" or so of fish mass per ~10gallons (ideally). Not a firm/hard rule as mass is more the thing rather than length, but it gives a feel for the ‘formula’. Tanks with better ammonia-handling abilities (more gravel surface area and filtration basically) can handle more, but it gets harder to keep things healthy long term. Ever notice how those tanks with lots of ‘feeder’ golds often have dead ones on bottom? Gotta keep stress low for healthy fish, and more fish = more stress. I use word stress loosely here, of course.

Pond comets can handle cycling a tank no problem usually, but the fancy ones are more sensitive to ‘pollution’ in general. You can put in a comet (or two) as the tank re-establishes the bacteria in gravel/filter (about two months or so) then you can either add a few more or get other fish you prefer instead. Fish do like having things to ‘play’ around (or hide by, etc), and live plants help keep nitrates consumed overall. It all depends on how much mass is introduced into water, and how much of a load on the bacterial breakdown ‘system’ you use (undergravel filter, exterior filter, etc). HTH.

Cleaning is best done w/ dilute bleach, or simple ‘friction’ (scrubbing, per se). Rinse well and let water sit overnight instead of using dechlorinator (it degasses just fine). Don’t use much pressure in scrubbing as it can weaken the seams - been there/done that and it sucks to ruin tank by own doings :wink:

9

I again second just a good simple cleaning, without any agents. I know that the local pet store near my house will test your water for free. You could clean your tank out, let it is cycle for a few days, and then bring a sample in. They will tell you if it is good for fish, yet. You might be able to find something similar where you are.

Beware that gold fish can be a long term commitment. I had a goldfish I got at a fair when I was 10. He lived until after I had graduated college, I think 15 years. He was in a ten gallon tank, by himself, and ultimately grew to be about 4 inches long.

10

Here I thought this was a response to the BP disaster, and concerned with what happens to the planet after we’ve destroyed every living thing in the ocean. Glad to see you’re a little less global that that.

11

I totally forgot to mention that if you want or need to clean off the ‘water spots’ or build-up of scale/hard spots that can occur at upper areas of the glass or upon equipment, vinegar works great. I am talking about that crusty stuff that can be seen along edges along waterline and/or on the cover (if used). If water has dissolved minerals (hard water, per se), there tends to be more than if you use softer (or reverse-osmosis sourced) water for the tank. This is usually more of an issue for salt-water tanks, but I’ve seen some pretty grungy freshwater tanks that could’ve used a bit of attention in this area.

12

Bleaching is to eliminate disease transfer. There is also no reason to worry about bleaching the stuff after all the fish are dead. I’ve used bleach to sterilize tanks and equipment for 40 years. Be sure to give the couple days rest for bleach traces to disappear.

Shudder? That’s a bit mellow dramatic.:rolleyes:

13

Yes, tell us why the neons and all the other fish died- just their time, a fish plague?

14

okay, folks…forgive me…:

I know a family that had a huge fish tank built into the wall of the living room. After a divorce, the husband (who cared for the fish) moved out, and the wife who remained in the house didn’t know how to care for them.

Result: an aquarium , permanently built into the wall, unmovable. An aquarium with NO fish in it.

But it had pretty little plants, and pretty rocks on the bottom, (and, yeah, a tacky plastic pirate ship that made a stream of bubbles).So the aquarium remained in the living room for years: a pretty little thing, an interesting conversation piece…but with NO fish in it.
And ya know what…? It really doesn’t matter!
Guests still enjoyed looking at it, and it was funny, and it needed no cleaning, (and it was a great butt for jokes about the ex.)

so may I suggest:…why bother filling it with all that livestock?

oh yeah, one more thing:
" so long, and thanks for the fish…"

(d & r)

note to mods: hey, I already asked for forgiveness once. I hope that’s enough :slight_smile:

15

I don’t see anything wrong with using bleach to clean the water. Bleach evaporates pretty quickly (say a couple of days at the longest), so there won’t be anything left by the time new fish are added. (From my days in managing swimming pools, I can assure you: if bleach was not continually added, it’d all be gone within a few hours on a nice sunny day.)

I’d agree with those who caution against soap or any cleaning implement that has ever encountered soap. Soap does not evaporate.

The 1" per 10 gallons rule is the best way to go, but you can exceed that limit if you’ve got good filtration, tough fish and you take good care of the water - change out a gallon or two a couple of times a week and don’t let algae build up.

Confession time: I started with four of those little tiny $0.29 goldfish in a 10 gallon tank. The biggest one is now topping 5" long. Those guys eat everything I put in the tank and continue to grow. (In fact, if I don’t feed them to their liking, they’ll splash water on me). They’ve now survived over 18 months. I would trade them back to the pet store for smaller ones, but I’m planning on building a koi pond this summer and want to use goldfish as test subjects to make sure my predator defenses are adequate before I invest in koi.

16

To clarify some things:

I know nothing about fish. The tank isn’t mine. My boyfriend bought it when we broke up because it was too quiet in the house and because he likes to look at fish. We’re back together now and I like fish too so we both want to keep it going.

The fish didn’t die of disease. He had a lot of trouble keeping them alive. We just found out that 1 of the fish we had (which he had been told was a good community fish) is actually a night stalker and was likely killing off all the other fish. The snail was a year or so old and died 2 or so months ago. The stalker fish just died. He has been hiding out in the castle for so long and we’d periodically flip the castle to see if he was still alive.
I don’t know why Adam decided to try goldfish. I like them because they’re pretty and those teeny neons are generally boring and hard to see across the room.

A long time commitment fish is a good thing. It really bothers Adam when his fish only lasts a few months. He almost cried when his 2+ year old neon died.

We didn’t know if the other fish would have left anything unsafe for goldfish, which is why we didn’t know if regular cleaning would be enough.
We had actually considered plants only but I think that looks better in a larger tank than what we have. I would like to do that eventually though.

17

Well, if the tank is not diseased, there is no reason to bleach anything.

Test the water quality, clean items as I described above (i.e. remove algae buildup and whatnot) and assuming the water quality is OK, introduce a gold fish or two.

18

Sounds good! Thanks for the advice everyone.

19

Probably more important than cleaning the tank is cycling the tank properly for the new fish.

It may not be obvious, but there’s a whole series of nitrogen chemical changes a water tank goes through when one adds fish, before it settles into a stable and safe water chemistry. If you just put fish into a clean new tank, most or all of them will die horribly.

Also, once one has a cycled and stable tank, it’s important not to clean it too clean – bacteria on the rocks and pebbles serve critical functions in turning fish waste into clean, breathable water for the fish.

Nitrogen cycle

Fishless cycling

Aquarium cycling

You can look up lots of similar links. Once you learn why and how, it’s probably more humane and a lot less gross to do “fishless” cycling and introduce the fish to an already-safe tank instead of fishing out half-dead sufferers covered with spots and open sores and having to find a way to euthanize them. I speak from gruesome first-hand knowledge.

20

BLEACH. BLEACH BLEACH BLEACH BLEACH BLEACH.

I worked in a pet store for almost ten years. I was the fish room manager for three of those years. I ran my own aquarium design/maintenance business on the side for eight years. Let me tell you about an aquarist’s best friend:

BLEACH BLEACH BLEACH BLEACH BLEACH.

First of all, just for minimal quarantine reasons–you honestly don’t know what microscopic beasties are in there. But trust me, they’re there. I ALWAYS bleached tanks between occupants, whenever possible. It’s just standard hygiene for most serious aquarists.

Second, chlorine bleach is extremely unstable. Unlike soap, it evaporates. Rinse well–for added assurance, your final bleach can be with a dechlorinating agent–and let dry. Once well rinsed and fully dry, it will be 100% bleach free and perfectly safe.

In the pet store where I worked, the nets were all kept in a bucket of bleach water, and simply rinsed under the faucet before each use. Absolutely safe.

And believe the people who tell you that you’ll be much happier with your goldfish if you limit yourself to 2 or 3. Get fancies if that makes them more appealing–but then be very sure there are no sharp points–rocks, sticks, whatever–in the tank: the more extreme fancy goldfish breeds are basically deformed, some are verging on crippled, and they bump into things. If you get bubbleyes, make sure your gravel is tumbled, not broken up with sharp edges.

Do NOT feed every day. Feed every two or three days, less in the winder. I usually feed goldfish once a week in the winter. Change the water as frequently as you can talk yourself into. Think of a partial water change like you’re opening up a window and letting in fresh air. You can do up to a third a day, if you’re fanatic, but scheduling 20 minutes once a week will be a couple pounds of prevention. Throw some aquarium salt in the water; roughly 1 teaspoon per 2 gallons. Maintain this when you change the water: change a third of a 30gal tank? put in 5 tsp aquarium salt each time. Sea salt is not just sodium chloride. It’s LOTS of crucial minerals that a lot of municipal water supplies lack.

Feed sinking pellets. Goldfish can gulp air when they feed at the surface. This is rarely a problem, but when it is it’s a doozy; they can get air trapped in their digestive system and float on their sides while you panic and think they’re dying. If this happens, feed them a couple of canned peas, crushed between your fingers. The roughage will usually push the air through. Fish farts!

Feed only enough for one feeding at a time. Don’t put in extra for later; you’re just feeding the bacteria. And not the good bacteria. A fish’s stomach isn’t much bigger than its eyeball. I’m not sure how universally true that is, but it’s a rule of thumb that has served me well. Never feed them more than that at a feeding. If you adhere to this strictly, you can feed more than 2 or 3 times a week. But most people have trouble doing one or the other.

Uh, all I got for now. Good luck!