How many fish for a 47 Gallon (180L) tank?

[Haywire]

Hi, I'd like to put Neon Tetras and Guppies into my 47 gallon planted aquarium (currently empty).

If I were to do a 50/50 split, how many of each could I comfortably put in? The happiness of the fish is the top priority and I'd like to keep some room available in case I decide to add more fish in the future.

Thanks!

 

[Essjay]

I'm afraid neon tetras and guppies are not compatible. Neons need soft water while guppies need hard water.

If you could tell us the hardness of your water, we can suggest fish - and how many - would be suitable for your tank. Your water provider's website will probably give your water hardness - we need a number and the units, not some vague words. If it's not there, take a sample of yuor tap water to an LFS and ask them to test GH (and KH). Again, we need numbers and the units. (There are half a dozen different hardness units and we need to know which one the website or LFS uses)

 

[Haywire]

In Clark Degrees, my water is 10.45. This is apparently 'slightly hard'.

That's disappointing to learn, especially after being told by the fish store employee that guppies and neons are "absolutely compatible". Certainly for the best though.

In that case, I'd be grateful to hear what kind of fish you would suggest. Thanks for the advice ^

 

[Essjay]

Shop workers are just about the worst people for giving advice. Most either don't know or don't care and will make up anything to make a sale.

10.45 deg Clarke converts to 8.3 dH and 149 ppm. dH and ppm are the two units used in fish keeping, fish profiles use one of those two.

Neon tetras' hardness range is 18 to 251 ppm, and guppies' range is 143 to 536 ppm. It is best to keep fish that have your hardness in the middle of their range. As you can see, despite being 'slightly hard', neons are better suited to your water than guppies.

There are many other fish that would suit your water, too many to list here. But in that sized tank you could easily have 18 neons and the same of a similar sized fish. The best thing would be to go to your local shops, all of them, and make a note of the fish that catch your eye. Then post them on here.




Have you cycled the tank yet? Or does the tank have lots of live plants?

 

[eaglesaquarium]

I agree with essjay.

Your water will allow a multiplicity of fish species be kept in that tank. And the size of the tank will also open up a lot of options.



I'd suggest starting with about a dozen neons for the baseline of your stocking plan.

Corydoras (with sand)
Smaller cichlids (apistogrammas - not all but some of the species cacatuoides would be ideal) - very colorful fish to give you the splash of color you are missing with the guppies.
BN pleco - whiptail catfish...

and then plenty of shoaling species you can look at as well. You'd likely want some more in the upper-mid level, as neon stick to the lower 1/3 overall.

 

[Haywire]

Thanks for the information, I'll have a look for some fish to go with the neons. The tank has been fully and properly cycled over a few months.

I quite fancied swordtails and Cory Catfish (although I have a gravel substrate which may not be suitable for the catfish?) so if either of those were compatible I'd be happy with that. Otherwise, I'll have a look round some shops next week (they all seem to close around 5 pm week days).

EDIT: I will put some live plants in before I add any fish

 

[eaglesaquarium]

Sadly, swords will also require hard water, harder even than the guppies.

And the cories really should be kept on sand, as much as possible.

 

[AbbeysDad]

Some folks get really hung up on hobby 'rules' that are more myths than laws.
My water is neither hard nor soft with a pH of 7.6....In my 60g I have Angels, neons, cories, and swordtails (and have for years) and they all do just fine! (I also bred, raised, and sold 50+ Mollies).
In the wild, some fish are found in waters either hard or soft so hobbyists think that's the only water they can be in. In reality, many of the fish we see in the hobby are bred and raised in tanks and/or ponds with various water chemistries, often nowhere near the same as if they were found in, or caught from the wild.
I'm no expert, and others will disagree, but I have been in the hobby for 50+ years and In my opinion, based on my experience, most fish can do nicely in water chemistries that differ from their 'wild' cousins. It's far more important to have and maintain clean, fresh water that's as pollution free as is possible. You don't do this with filters, but rather fast growing plants and routine partial water changes.

As to your question @Haywire, there really is no precise answer. (And I cringe at the silly 1" per gallon 'rule'). In a 47g tank, anything over say about 15-20 small fish could be considered crowded. But crowded is a relative term. If the water quality remains high due to increased maintenance, more fish can live well in the same space. We run into trouble when we slack off even with fewer fish in polluted water. In reality, the larger the tank and the smaller the bio-load tends to produce the best results as water quality remains better, longer.