How long will my fish last?

[Lark's Song]

About a week ago, my mom and I set up my 20-gallon. We're really new to this, but the people at our local Petco seemed to really know what they were talking about. On Friday, we bought three fish- a gold dust molly, a red platty, and a sunset fire platty.

The platties were small compared to the molly. The molly could move seemingly three times faster than any of the others.

Earlier today, when I got up to feed my fish, I forgot to turn on the light. All my fish were really active and seemed fine.

I realized the light was off when I got back from school. I turned it on, but I couldn't find any of the fish. I panicked and grabbed my mom immediately. All three were lying on the gravel, not or barely moving.

After a few minutes of the light being on, things began to pick up. My mom promised she'd watch them and do everything she could while I did my homework. She watched them for about 20 minutes and everything was fine.

When I went to feed my fish earlier tonight, I couldn't find the molly, which was strange, because she is usually very active and easy to spot. The plattys were swimming together, very typical. I eventually found the molly's dead body resting in one of my plastic plants. Her fins were plasetered to her body, and her eyes appeared darker than they had been. She fell through the water like a stone instead of wriggling her way through like a puppy. She was dead as a doornail.

Are my platties next? How long will they last? How many more fish will follow in my molly's footsteps before the nitrogen cycle is complete?

 

[FishDad]

the people at our local Petco seemed to really know what they were talking about.

They don't. Don't listen to them.

Your nitrogen cycle will likely take a month to complete. What you guys need to do is buy a test kit and an ammonia detoxifier. Do daily 50% water changes. Test the water and add the detox as needed. Keep doing the water changes until your ammonia and nitrite are ZERO and your nitrate is around 20ppm.

 

[exhumed07]

welcome to the tank. listen to fishdad, he knows what he is talking about lol. if u have a small mom and pop fish store i would recomend going to them. they could 1 use the business, 2 are generally mor knollegable, 3 normally they will not sell u things u do not need.

the nitrogen cycle will take a while with a 20 gallon only having 2 fish in it it could happen over the course of 4 months and u may not even know it happened. if say u had 20 fish in it then it will be very noticable and take about 3-6 weeks or so and will be more stressful for the fish. when u get a test kit the first thing u will notice will be the ammonia going up. after a while with doing water changes u will notice the water will cloud up and then clear up and u will not register ammonia or at least should not. that cloudiness is a bacteria bloom. the bacteria feeds on the ammonia turning it into nitrites. another toxic chemical. but again after a while with regular water changes u will notice it getting cloudy again. that is another bacteria bloom and that bacteria will feed on the nitrites. once the cloudy water goes away u should register no ammonia and no nitrites but there will be nitrates which are harmless but act as a food for plantlife such as algea. normally in a well maintained tank the nitrates will be around 20ppm as fishdad said. after all that is said and done your tank will be cycled. and with a cycled tank u can put in more delicate types of fish. when i started out i knew nothing about a cycle and bought 10 neons for a 10 gallon tank. within a week all of them were dead. it's a common mistake or lack of knowing that causes this and i'm sure most everyone on here has been there. just keep an eye on the ammonia and nitrites and do daily water changes of about 50% and things should turn out fine.

 

[FishDad]

when i started out i knew nothing about a cycle and bought 10 neons for a 10 gallon tank. within a week all of them were dead. it's a common mistake or lack of knowing that causes this and i'm sure most everyone on here has been there.

Same here.

 

[OrangeCones]

I forgot to turn on the light.

No light on will not bother the fish. The light is more so we can see them, and to help plants grow if you have live plants.

Are my platties next? How long will they last? How many more fish will follow in my molly's footsteps before the nitrogen cycle is complete?

You can help the fish survive the 'fish-in' cycle by doing a lot of water changes. Do you use a dechlorinator? If so, what brand? Some can be used to detoxify (temporarilty) the ammonia and nitrite buildup.

 

[Mawade1984]

I used "prime" to get mine started, and I still have all 5 of the original fish plus all the ghost shrimp. I put that in, my live plants, and let the aquarium run for about 3 days before going to LFS to get fish. The prime has dechlorinator, bacteria, reduces ammonia and nitrate, an something else I can't remember without the bottle in front of me!

 

[FishDad]

Prime doesn't have bacteria in it.

 

[Lark's Song]

Thanks for the advice, everyone. I did use a dechlorinator, but I can't remember what brand.

Update: the sunset fire platty is now dead as well.

 

[FishDad]

Water changes!

 

[Mawade1984]

Fish dad now that I'm home looking at it your right. I was getting something else mixed up with it. I knew I had bacteria. Thought it was prime. Instead I have prime and superbac live! Nitrifying bacteria

 

[FreshyFresh]

Sorry for your losses Lark! It's a common beginners mistake. We've all been there.

I have to say though that I am surprised 3 small fish soured 20gal worth of water enough in ~5days, for all of them to die. I happens I guess.

Like fishdad suggested, you need a water parameter test kit. An API master test kit is very popular and easy to use. Measuring for ammonia, nitrite and nitrate is ESSENTIAL for setting up and maintaining a tank. Measuring for things like pH is not that important.

If you want to keep your tank setup and you don't want to do a fishless cycle by adding ammonia, go back to petco or petsmart, get a bottled cycle starter product and 1-3 small, hardy fish like zebra danios and follow the instructions on the bottled cycle starter product. In my area, the LFS's are as clueless to starting up a tank as any place else.

What type of filtration are you running on the 20gal? What's your water temperature?

 

[Lark's Song]

I don't know what to call the filter at all. All I can say is it bubbles. The temperature is a consistant 75-77 feirinheit (typo?).

Also, the red platty is still alive.

More news: one of the platties decided it's be a good idea to have babies. Yep. We bought a pregnant fish. Now I have about three fry and countless more dead, their bodies trapped between the rocks. What do I do? How do I get the bodies out when I can't even find them all?

 

[Lark's Song]

Also, thanks to everyone for all the pointers.

 

[exhumed07]

Um no real way to get rid of the dead besides a gravel vac.

 

[FreshyFresh]

Lark, if all you've got is a single air-powered sponge/floss filter running in that 20g, that's not enough unless you're prepared to do daily water changes IMO.

I run two bubbler filters in my 29gal, but that's also with a Top Fin 30, hang-on-back (HOB) filter running too.

 

[Thyra]

If a dead shrimp works to help cycle a tank, I suspect the dead fry will also help. Besides the mother probably ate some of them.

 

[OrangeCones]

A sponge filter provides a lot of surface area for the beneficial bacteria. Although I've never used one air-pump driven (I use small submerged powerheads), one should provide plenty of places for the bacteria to be cultured. I keep 2 in my 40gallon tank, but kept only 1 tanks ranging from 5 to 29 when I had muliple tanks.