Tropical fish for a 20 gallon?

[Corydoras_Catwoman]

Hi, I have been doing research on fish for many years and have kept freshwater tanks for ever. This is my first time setting up a tropical tank and I’m struggling to find small ‘feature fish’ for my 20 gallon high.
Just a note: I’m definitely going to keep some guppies, neon tetras and Corydoras Catfish so the water temp. for this fish can’t really be higher than 78F ish.
I have aquarium sand substrate, four plants including two anubias species and microsorum pterupus. Lots of places to hide and about 3/5 of the tank to swim around in. I have been researching species of gourami but feel that it would be cruel to put a dwarf gourami in its own in a 20 as they are usually kept in pairs/trios? Is it big enough for two females?

 

[Colin_T]

Hi and welcome to the forum

Hi, I have been doing research on fish for many years and have kept freshwater tanks for ever. This is my first time setting up a tropical tank and I’m struggling to find small ‘feature fish’ for my 20 gallon high.

Can you explain this bit. You have kept freshwater tanks for a long time but this is your first time setting up a tropical tank.

It seems contradictory. If you have kept fish before, surely you have set up tanks before?

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What are the tank dimensions (length x width x height)?

What is the GH (general hardness) and pH of your water supply. This information can usually be obtained from your water supply company's website or by telephoning them. If they can't help you, take a glass full of tap water to the local pet shop and get them to test it for you. Write the results down (in numbers) when they do the tests. And ask them what the results are in (eg: ppm, dGH, or something else).

Livebearers (guppies, platies, swordtails, mollies) naturally occur in water with a GH above 200ppm and a pH above 7.0.
Tetras, gouramis, Corydoras occur in soft water with a GH below 150ppm and a pH below 7.0.

I don't recommend keeping livebearers with tetras because they require different water chemistry. If you have soft water the livebearers will struggle, and if you have hard water, the tetras, gouramis and Cories will struggle.

You need to find out what your GH and pH are and get fish suited to your water. If you want fish that require different water chemistry to what you have, you will need to modify your water.

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How long has the tank been set up for?

Has the filter cycled (developed the beneficial bacteria that keeps ammonia and nitrite levels at 0)?

 

[Essjay]

A second everything Colin has said

Looking at the photo of your tank, you seem to have left the plants in the baskets they came in. You need to take them out of the baskets and carefully remove any packing from round the roots. The anubias and java fern (Microsorum pteropus) must have the rhizome above the substrate; if the rhizomes are buried they will rot. The usual way to grow them is attached to decor. The rhizome is then above the substrate and the roots can grow down into the substrate.

 

[Corydoras_Catwoman]

A second everything Colin has said

Looking at the photo of your tank, you seem to have left the plants in the baskets they came in. You need to take them out of the baskets and carefully remove any packing from round the roots. The anubias and java fern (Microsorum pteropus) must have the rhizome above the substrate; if the rhizomes are buried they will rot. The usual way to grow them is attached to decor. The rhizome is then above the substrate and the roots can grow down into the substrate.

Hey, thank you for replying so quickly. The two in the pots are anubias and the aquatics centre told me to leave them in the pots until they root? The other two are planted properly...should I take the anubias out of the pot?

 

[Corydoras_Catwoman]

Hi and welcome to the forum


Can you explain this bit. You have kept freshwater tanks for a long time but this is your first time setting up a tropical tank.

It seems contradictory. If you have kept fish before, surely you have set up tanks before?

--------------------------
What are the tank dimensions (length x width x height)?

What is the GH (general hardness) and pH of your water supply. This information can usually be obtained from your water supply company's website or by telephoning them. If they can't help you, take a glass full of tap water to the local pet shop and get them to test it for you. Write the results down (in numbers) when they do the tests. And ask them what the results are in (eg: ppm, dGH, or something else).

Livebearers (guppies, platies, swordtails, mollies) naturally occur in water with a GH above 200ppm and a pH above 7.0.
Tetras, gouramis, Corydoras occur in soft water with a GH below 150ppm and a pH below 7.0.

I don't recommend keeping livebearers with tetras because they require different water chemistry. If you have soft water the livebearers will struggle, and if you have hard water, the tetras, gouramis and Cories will struggle.

You need to find out what your GH and pH are and get fish suited to your water. If you want fish that require different water chemistry to what you have, you will need to modify your water.

--------------------------
How long has the tank been set up for?

Has the filter cycled (developed the beneficial bacteria that keeps ammonia and nitrite levels at 0)?

Hi! Sorry that was really unclear. I’m new to the forum. I have kept freshwater (cold/temperate) tanks for years, with a filter and pump but have never needed a heater or dealt with tropical fish. I have also never used anything larger than a 10 gallon so this is a little daunting.
The tank is not set up yet. I am awaiting the arrival of my heater, filter and light while the water settles. The pH was 7.1 bang on
And the ammonia, nitrate and nitrites were all ‘slightly higher than you want’ as I was told by the aquatic center. Sorry for lack of detail.

 

[Corydoras_Catwoman]

Oh and the tank is a 20 gallon high, 24” x 16” x 12”

I wasn’t told the GH put I’ve now located a more reliable source for my fish and I’m taking a water sample in this week. The other place didn’t really know what they were talking about and even tried to sell me a common pleco as a ‘small aquarium fish!’

 

[Essjay]

The first lesson is don't believe the shop. You do need to remove all the plants from the pot, and if you leave the anubias and java fern with the rhizomes in the pots they will start to rot. The rhizomes are the thick root-like structures that the leaves grow from; the roots themselves are very thin. they can be allowed to penetrate the substrate but the rhizomes must be above the substrate. The easiest way to achieve this is by attaching the rhizome to a piece of decor and letting the roots grow downwards.

Do you still have the cold/temperate tanks? If you do, you can use some of their media to kick start your cycle. The other choices are to get a lot more plants, faster growing species than java fern and anubias, and use them to remove the ammonia made by the fish, uneaten food etc. Floating plants are particularly good for this, and a lot of fish need the cover they provide. The other option is to remove the plants temporarily and do a fishless cycle using ammonia.
If your ammonia and nitrite are 'slightly higher than you want' the tank is not ready for fish yet. Rather than rely on a shop to test those, you do need your own test kit. For pH you need the reading of a freshly run sample of tap water and one that has been allowed to stand for 24 hours - they'll probably be different.

 

[Colin_T]

Freshwater tropical fish are the same to care for and maintain as freshwater coldwater/ temperate fish. The only real difference is the heater.

Big tanks are the same to look after as small tanks, they just take up more space. You still do the same work on them.

 

[Ozzie Boss]

Depending on how your water tests out ,GH, you could try a honey gourami. They are a peaceful dwarf species of gourami. They usually are not contaminated with Iridovirus or Tuberculosis which are commonly found in other dwarf species like powdered blues. I would do a single male, however you mentioned you wanted more then one. You can try a male and a female, 2 females, or 2 females and 1 male but this most likely won't work in a 20 gallon. Good luck.