Which fish in 20 gallon

[Creepy the Crayfish]

I have a fully cycled 20 gallon tank I was wonder ing if this would be a good setup: 6 chilli rasbora 3 guppys and 3 corys. Is this too many fish?

 

[Colin_T]

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).

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Rasboras & Corydoras normally occur in soft water, whereas guppies naturally occur in hard water. Depending on what the GH is will determine which fish you should keep.

 

[Creepy the Crayfish]

I haven't tested gh or ph but if i did get those fish would i have to keep the ph in the middle? Or should i find other fish

 

[Colin_T]

Rasboras naturally occur in water with a GH below 150ppm and a pH below 7.0
Guppies naturally occur in water with GH above 200ppm and a pH above 7.0

 

[Creepy the Crayfish]

So thats a no?

 

[Guppylover3x]

So thats a no?

Hello and welcome to the forum
What Colin is trying to say is that it can be difficult to keep these species together because they both require different water requirements. You could never keep both species happy it would be one or the other. Hope this helps. Best of luck.

 

[Byron]

Following up on what has been posted. It is much easier to keep fish suited to your source water parameters. Adjusting parameters like GH and pH is not usually easy. The GH, KH and pH are closely tied to each other, which means that attempts to change for example the pH will tend to be dangerous unless the GH and KH are also adjusted. So we start by knowing the GH, KH and pH of the source water. These numbers will tell us what the pH may do in an aquarium; pH is affected by natural biological processes, but the GH and KH impact the degree to which this may occur.

You should be able to get the GH, KH and pH of your source water from your municipal water authority. Check their website if they have one, or call them. Make sure you get the number and (for GH and KH) the unit of measure they use.

While I'm here, to your initial question, the fish species/numbers are not too many, in fact they are too few for the rasboras and cories. These are shoaling species, which means they live in large groups and they must have a decent-sized group in an aquarium. Five or six cories is minimum, and the dwarf (chili) rasbora are better with 9-12. But before rushing into that, we must get the parameters nailed down.

 

[TO KYO]

I haven't tested gh or ph but if i did get those fish would i have to keep the ph in the middle? Or should i find other fish

I would highly recommend you to know your ph and gh of your aquarium more than anything. I learned it the hard way

 

[Creepy the Crayfish]

Ok thank you i will try to figure out all that stuff.

 

[Creepy the Crayfish]

I know u already told me this wouldn't work but when I went to study the ph that the fish needed online it said guppies ph was between 7.2-8.2 corys was between 7-8 and chili Rasboras were up to 7.8

 

[Creepy the Crayfish]

Is this true or can they live in these conditions just not happily?

 

[eaglesaquarium]

I know u already told me this wouldn't work but when I went to study the ph that the fish needed online it said guppies ph was between 7.2-8.2 corys was between 7-8 and chili Rasboras were up to 7.8

What resource are you using?

Chili Rasbora (aka Mosquito Rasbora)
http://www.seriouslyfish.com/species/boraras-brigittae/
pH 4.0 - 7.0

One of the more common Corydoras (Corydoras Aeneus)
http://www.seriouslyfish.com/species/corydoras-aeneus/
pH 6.0 - 8.0 (though, I'd definitely lean far to the lower side of that... most cories will be far lower than that... and coming from Amazonian tributary waters, low pH is much more common)

Guppy (Poecilia reticulata)
http://www.seriouslyfish.com/species/poecilia-reticulata/
pH 7.0 - 8.5


And this post doesn't address the hardness issues, as has been alluded to... (the rasbora and cories preferring much softer water - and the guppies preferring significantly harder).


It can work for a while... but keeping these fish together really isn't in their best interests.

 

[Creepy the Crayfish]

So it CAN work but isn't good for them?

 

[Essjay]

In my opinion, matching your water hardness to a fish's requirements is more important than matching the pH.

It's due to the way fish handle the 'hardness' minerals in the water. Soft water fish have evolved in water with very few minerals. Put these soft water fish in hard water and their body absorbs the minerals. But having evolved in soft water they have not developed a way to remove all the excess minerals so they build up inside the fish. This slowly kills the fish.
Hard water fish have evolved in water with lots of minerals. They bodies have evolved so that they can deal with the excess minerals. Put hard water fish in soft water and there are not enough minerals for the fish to absorb. As a result, they get sick more easily and don't live as long a life as they should.

This is why we should not keep hard water fish and soft water fish in the same tank. If you want both, you need separate tanks and adjust the water in one of them. If you have soft water, you add minerals to the tank with hard water fish; if you have hard water, you mix tap water with pure water to dilute the minerals. But this means adjusting the new water at every single water change, forever. It works out expensive over the years.

 

[Creepy the Crayfish]

Ok thank you very much I cannot get my water tested for awhile still so I won't know for sure for awhile.