New here..just a few questions :)

Hi everyone, my daughter and I are venturing into the tank life for the first time and through most of my research im pretty excited so far. My main questions are, are there any freshwater sharks that can fit in a 20g tank, How many fish fit in a 20g tank as I don't want to cramp them, my daughter wants tetras so how many do I need for a school?

 

I don’t believe there are any sharks that can go into a 20g, you’re generally looking at a 40 breede rminimum for them. As for how many fish that’s dependent on what you get. We can help you build a stock if you’d like.
Tetras need a school of at least 6 of the same species.

welcome to fishlore and the hobby! I hope you enjoy it!

 

1. No.
2. Well what tetras? There are multiple species of tetras. Generally though around 6-8.

Welcome to fishlore

 

Yeah I would say no sharks in a 20 too....sorry. Tetras vary in size for sure. We would need to know which ones you were looking at.

 

sorry my fault, my daughter wants to the glofish ones im not sure the technical name for them but i think longfin? they arent the skinny ones but the bigger looking ones. Darn I really wanted a shark, oh well. So far im looking at some tetras for her some guppies and a bristlenose pleco. How do I build a stock?

 

I think glofish tetras and guppies will be fine. Personally I wouldn't do a bristle nose pleco in anything less than a 29 gallon.

 

If it's the glo variety those are skirt tetras, which are larger than some others like neons, cardinals, or embers. Is it a standard 20, or a 20 long? You have a little more flexibility with a long because of the larger footprint and surface area.

 

The black widow glo tetras? And to build a stock you basically just figure out what fish are compatible with eachother and how much of each is acceptable in the tank.

for example; with your stock all the fish should be compatible so you pult do something like
6-8 glo tetras
1 bn
5-6 male guppies.
This is dependent however on the dimensions of the aquarium. Is it a long or tall 20g?

 

The BN I would wait for awhile on, like 6 mos or so. They like well established tanks.

 

I think glofish tetras and guppies will be fine. Personally I wouldn't do a bristle nose pleco in anything less than a 29 gallon.

Is a 20 too small for them?

If it's the glo variety those are skirt tetras, which are larger than some others like neons, cardinals, or embers. Is it a standard 20, or a 20 long? You have a little more flexibility with a long because of the larger footprint and surface area.

See i wish i had known that before I bought a standard 20g tank, but its a standard.

The black widow glo tetras? And to build a stock you basically just figure out what fish are compatible with eachother and how much of each is acceptable in the tank.

for example; with your stock all the fish should be compatible so you pult do something like
6-8 glo tetras
1 bn
5-6 male guppies.
This is dependent however on the dimensions of the aquarium. Is it a long or tall 20g?

Awesome that sounds great! It is a regular 20g or tall i guess which seems to be the less ideal version :/

The BN I would wait for awhile on, like 6 mos or so. They like well established tanks.

Okay good to know, is it possible to have a bn and shrimp or one or the other?

 

Can I ask what inspires you when you think of an aquarium? Do you and your daughter like a natural look or more vibrant colours (talking everything but the fish). Planted tanks are lots of fun and great for your fish but have specific needs than artificial plants and resin decor.

Have you researched the nitrogen cycle?

Have you put together a budget for all of the equipment and consumables you'll need (it's a lot)

If you like Youtube, we can suggest inspo channels.

There are small fish that look shark like, but so many other fascinating fish to consider. Lots of species info on this forum. If you make a stocking list, we can help you whittle it down as species compatibility is very important.

Welcome!

 

I have a BN and Amanos. so yeah

 

Can I ask what inspires you when you think of an aquarium? Do you and your daughter like a natural look or more vibrant colours (talking everything but the fish). Planted tanks are lots of fun and great for your fish but have specific needs than artificial plants and resin decor.

Have you researched the nitrogen cycle?

Have you put together a budget for all of the equipment and consumables you'll need (it's a lot)

If you like Youtube, we can suggest inspo channels.

There are small fish that look shark like, but so many other fascinating fish to consider. Lots of species info on this forum. If you make a stocking list, we can help you whittle it down as species compatibility is very important.

Welcome!

My daughter is only 5 so she likes the neon vibrant bright colors, for me personally i was looking at the redtail shark i love the look but thats out the window now. So I'm really open to anything as long as they are compatible with the tetras. I definitely want to make sure the fish in the tank are all compatible
EDIT: Yes i have looked up the nitrogen cycle, when i bought the tank i bought a bio booster and water conditioner. I tested the water today and no Nitrite and ammonia was .25ppm the ph seemed a little high 7.6

 

So it’s

24 1/4 x 12 1/2 x 16 3/4

?

you should still be able to go with the tetras and guppies but the bn likely wouldn’t do the best in a tall. In a 20 long I think it would be fine (I’ve kept multiple bn’s myself),but the tall just doesn’t have that space.

 

So it’s

24 1/4 x 12 1/2 x 16 3/4

?

you should still be able to go with the tetras and guppies but the bn likely wouldn’t do the best in a tall. In a 20 long I think it would be fine (I’ve kept multiple bn’s myself),but the tall just doesn’t have that space.

bummer, are there other plecos that would fit in a 20g tall tank?

 

Some will tell you 20 is fine, but again it seems cramped to me as a long term tank for bn plecos.

Vibrant colors? Sorry if this is a dumb question but are you looking for beginner fish only? Fish on the larger or smaller, or fine with both? Fish that easily breed or no babies?

 

bummer, are there other plecos that would fit in a 20g tall tank?

Not really, bn’s and clowns are some of the smaller ones but they need that length. Unfortunately the tall can’t provide that. Have you set it up at all yet? Just curious because if not and you really want a long you could likely return/swap it out.

 

Bite the bullet now....get a 55 gallon, you will out grow the 20 very quickly, larger tanks are easier to maintain.
Then you could get 1 rainbow shark in there and he will be amply happy, you could stock like 15 tetras at that point and the BN pleco and some snails to make up the clean up crew.
Use live plants not fake ones as they help maintain a good environment.
Seachem Prime is your friend.
Do not clean your filter media,that is where the beneficial bacteria live.
Do weekly water changes.
Make hiding spots for the pleco and rainbow shark.
Get a little wave maker for a current and some air stones in the tank.
Only run the light 7 or 8 hours a day.
Dont leave the blue light on all night(fish sleep)
And have fun!

 

What is the pleco appeal? I ask as there might be a close second that suits your tank, depending on what floats your boat. (but the idea of switching out for a 20 long is awesome)

 

If you want some variety you could get some black skirt and/or white skirt tetras along with the glo ones. They're all the same species, and will shoal together.

 

Bite the bullet now....get a 55 gallon, you will out grow the 20 very quickly

Great advice, but the wrong advice( just kidding).
Skip the 55, and just get a 75.
That extra 5 inches in width makes a big difference.

 

Great advice, but the wrong advice( just kidding).
Skip the 55, and just get a 75.
That extra 5 inches in width makes a big difference.

Aaaahhhh, got me hahah ah aha.
Knowing what I know now I would have gone for my 55 first and totally skipped my 28 bow front,but glad I didnt because I love the little tank

 

Some will tell you 20 is fine, but again it seems cramped to me as a long term tank for bn plecos.

Vibrant colors? Sorry if this is a dumb question but are you looking for beginner fish only? Fish on the larger or smaller, or fine with both? Fish that easily breed or no babies?

its not dumb, i say vibrant because my daughter likes bright vibrant colors. Im personally open to all kinds of fish.

Not really, bn’s and clowns are some of the smaller ones but they need that length. Unfortunately the tall can’t provide that. Have you set it up at all yet? Just curious because if not and you really want a long you could likely return/swap it out.

I dont really want to swap it out personally

Bite the bullet now....get a 55 gallon, you will out grow the 20 very quickly, larger tanks are easier to maintain.
Then you could get 1 rainbow shark in there and he will be amply happy, you could stock like 15 tetras at that point and the BN pleco and some snails to make up the clean up crew.
Use live plants not fake ones as they help maintain a good environment.
Seachem Prime is your friend.
Do not clean your filter media,that is where the beneficial bacteria live.
Do weekly water changes.
Make hiding spots for the pleco and rainbow shark.
Get a little wave maker for a current and some air stones in the tank.
Only run the light 7 or 8 hours a day.
Dont leave the blue light on all night(fish sleep)
And have fun!

I unfortunately dont have the space for a 55 gallon tank, but in the near future that might be a possibility, id like to master this 20 gallon tank before i go up

What is the pleco appeal? I ask as there might be a close second that suits your tank, depending on what floats your boat. (but the idea of switching out for a 20 long is awesome)

The pleco appeal is that my wife loves plecos apparently and i had no idea. Im open to any suggestions

 

I guess I'm trying to figure out what she likes about them. The glass sucking business? the look of them? The fact that they hang out on the bottom? I mean there's hillstream and other loaches, stiphodons, pygmy corydoras...

 

I guess I'm trying to figure out what she likes about them. The glass sucking business? the look of them? The fact that they hang out on the bottom? I mean there's hillstream and other loaches, stiphodons, pygmy corydoras...

She apparently likes that they suck on the tank because it looks like they are kissing the tank and they look kind of like a shark, she also likes the pattern.

 

, i say vibrant because my daughter likes bright vibrant colors. Im personally open to all kinds of fish

I wanted my kids to enjoy my tank as well, and I went with the GloTetras you're looking at. I love mine, we actually prefer them in normal light. They are basically black skirt tetras if you want to Google them further. You're daughter would like them, they swim gracefully around and the long fin variety is pretty.

 

Look into corydoras on sand substrate. They are ADORABLE and fit nicely into a peaceful 20 gal tank. They sift through the sand, shoving their little heads all the way in there looking for food. Their little butts wiggle all over. Your kid will love them. I personally wouldn’t put a pleco in anything less than a 29 gal. Panda corys are super, extremely adorable. But there’s so many varieties. They do like established tanks, so I’d wait a few months before adding them to the tank. (I feel like most bottom dwellers prefer an established tank).

 

You could have 6-7 skirt tetras after the tank is cycled. And after the tank starts to grow algae you could add 6 ottos. Be sure that you have a significant amount of algae before adding ottos, as they are strict herbavores that may never adopt to eating packadged foods.
Another possability is a school of 6 stone catfish.
slightly less related to plecos =
6 dwarf cory cats, or 10 pygmy cory cats.

 

You could have 6-7 skirt tetras after the tank is cycled. And after the tank starts to grow algae you could add 6 ottos. Be sure that you have a significant amount of algae before adding ottos, as they are strict herbavores that may never adopt to eating packadged foods.
Another possability is a school of 6 stone catfish.
slightly less related to plecos =
6 dwarf cory cats, or 10 pygmy cory cats.

I will respectfully disagree about the otos. They're notoriously difficult to keep alive, and if luck was great and they all survived I doubt if a 20 gallon tank would have enough algae to feed them indefinitely.

 

I would skip the plecos in a tank that small. Otto's, Kuhli loaches, Cory catfish, ghost shrimp, and mystery snails could be good bottom feeders for your tank once it is cycled and growing enough algae

 

you guys have all been a great help, a few more questions. So when I went to the pet store they told me to buy water conditioner and a biological booster which i did as well. Am i supposed to be putting those in everyday? I did a water test yesterday and the tank has been up for 3 days and the reading was ph7.6 highph8.2 no nitrite ammonia .25ppm. How do i know once the tank has cycled and its safe to allow fish, also is my ph too high?

EDIT: I'm not going to be adding fish immediately or anything I'm more just curious how i know once the the tank is cycled and safe

 

Water conditioner only really need to be put in during waterchanges or in specific situations to help with parameters. What biological booster did you get?

Your ph should be fine for the species you are looking at. Your cycle will be finished once theres no ammonia or nitrite, but has some nitrates.

Since the tank is a long I wouldn't recommend most bottom dweller shoals like cories, otos, or kuhlis. Not enough room for them given the length IMO.

 

you guys have all been a great help, a few more questions. So when I went to the pet store they told me to buy water conditioner and a biological booster which i did as well. Am i supposed to be putting those in everyday? I did a water test yesterday and the tank has been up for 3 days and the reading was ph7.6 highph8.2 no nitrite ammonia .25ppm. How do i know once the tank has cycled and its safe to allow fish, also is my ph too high?

EDIT: I'm not going to be adding fish immediately or anything I'm more just curious how i know once the the tank is cycled and safe

There’s a toooonnn of threads here on how to do a fishless cycle. I’m not really sure what the biological booster is. But a fishless cycle is just adding some ammonia to the tank (like fish food) and waiting for bacteria to form, eat the ammonia, and convert it to nitrates (end product of cycle).

A water conditioner removes toxic chlorines from tap, so it is essential to add with each water change, or you will kill the bacteria (and fish when they’re in there). Most people here use Seachem Prime for their conditioner.

To speed up a cycle, you can add bottled bacteria from the store. Some people say it works, some don’t. It highly depends on whether or not any bacteria in that bottle are still alive. So it could help, or do nothing. Won’t hurt, anyway. You can also speed up a cycle by taking media from another tank and putting it in your filter. This media already has some bacteria, which then just has to repopulate.

Essentially, add ammonia and conditioner. Test for ammonia daily. You’ll start to see nitrites at some point, then eventually you’ll see nitrates. When all the ammonia you add can be changed to nitrates in 24 hours, you’ll see 0 ammonia, 0 nitrites, and some nitrates. your cycle is complete.

I respectfully disagree with the comments about not having any bottom feeders at all. People argue about whether or not pygmy corys fit in a 10 gal, but I’ve never heard someone say you can’t have corys in a 20 gal.

 

Water conditioner only really need to be put in during waterchanges or in specific situations to help with parameters. What biological booster did you get?

Your ph should be fine for the species you are looking at. Your cycle will be finished once theres no ammonia or nitrite, but has some nitrates.

Since the tank is a long I wouldn't recommend most bottom dweller shoals like cories, otos, or kuhlis. Not enough room for them given the length IMO.

Ah okay I see thank you, I got imagitarium bio booster. Okay perfect I was just using the test kit yesterday and I wasn’t sure if I was reading it right so I just wanted to know what I’m supposed to look for once the cycle is complete

There’s a toooonnn of threads here on how to do a fishless cycle. I’m not really sure what the biological booster is. But a fishless cycle is just adding some ammonia to the tank (like fish food) and waiting for bacteria to form, eat the ammonia, and convert it to nitrates (end product of cycle).

A water conditioner removes toxic chlorines from tap, so it is essential to add with each water change, or you will kill the bacteria (and fish when they’re in there). Most people here use Seachem Prime for their conditioner.

To speed up a cycle, you can add bottled bacteria from the store. Some people say it works, some don’t. It highly depends on whether or not any bacteria in that bottle are still alive. So it could help, or do nothing. Won’t hurt, anyway. You can also speed up a cycle by taking media from another tank and putting it in your filter. This media already has some bacteria, which then just has to repopulate.

Essentially, add ammonia and conditioner. Test for ammonia daily. You’ll start to see nitrites at some point, then eventually you’ll see nitrates. When all the ammonia you add can be changed to nitrates in 24 hours, you’ll see 0 ammonia, 0 nitrites, and some nitrates. your cycle is complete.

I respectfully disagree with the comments about not having any bottom feeders at all. People argue about whether or not pygmy corys fit in a 10 gal, but I’ve never heard someone say you can’t have corys in a 20 gal.

It’s supposed to have the good bacteria in it that is formed when the tank cycles, or so the pet store people told me.

 

Another question for anyone, when i set up the tank there was this kinda cloudyness to it and it went away but now it came back, am i doing something wrong?is the cloudyness normal?

 

Another question for anyone, when i set up the tank there was this kinda cloudyness to it and it went away but now it came back, am i doing something wrong?is the cloudyness normal?

Most likely a bacterial bloom during the cycle. I wouldn’t be concerned.

 

Since my tank is already set up can i add a live plant to it? or will it mess up the cycle or anything?
Also can kuhli loaches live in a tank with gravel?

 

You can add live plants any time you like!


How big is the gravel and is it smooth?

Have you looked into Hillstream Loaches? They do the glass sucking thing and if you stretch your imagination they kind of look like mini stingrays.

Just wanted to add to the confusion.

 

You can add live plants any time you like!


How big is the gravel and is it smooth?

Have you looked into Hillstream Loaches? They do the glass sucking thing and if you stretch your imagination they kind of look like mini stingrays.

Just wanted to add to the confusion.

cool, i just wanted to add a live plant and maybe a piece of driftwood. Its not huge but not small and i dont think its smooth it looks like rocks.
Cool ill check those out.
Confusion? llol

 

cool, i just wanted to add a live plant and maybe a piece of driftwood. Its not huge but not small and i dont think its smooth it looks like rocks.
Cool ill check those out.
Confusion? llol

Confusion. Everyone has thrown out all sorts of fish at you! And half of us say half of those fish can’t be in that tank! Haha, fishkeeping is certainly not a black-and-white hobby.

Live plants are amazing. Add them all! I picked low tech plants so I don’t have to do anything but squirt some liquid in there once a week.