# Will Be Setting Up A 42 Gallon NPT, How Many Guppies Can I Put In It?



## Tsin21 (Oct 12, 2017)

I will be soon setting up a 42.27 gallon NPT for my guppies and danios. How many guppies can I put in there? 
As of now, I have more than 30 guppies and I'm willing to rehome the excess.
Tank size: 80 cm (31.5 in) x 40 cm (15.75 in) x 50 cm (19.69 in) = 160 liters (42.27 gallons)

Planned stocking will be:
5 x Zebra danios
? x Guppies
Some red cherry shrimps
some trumpet snails, pond snails & nerite snails

As for the plants, I'll be trimming & transferring some from my main tank:
Amazon Swordplant
Hydrocotyle sp Japan
Ludwigia repens
Water Sprite
Cryptocoryne wendtii
Stargrass
Amazon frogbit
Rotala rotundifolia
Bacopa monnieri

I will pick up the tank this evening and set it up this weekend. I'll be putting an inch potting soil mix covered by an inch of sand.

Will post photos soon


----------



## hoppycalif (Apr 7, 2005)

Guppies are so small you can put a lot of them in that size tank. Many years ago I started out with a 10 gallon tank that at one time had almost 100 guppies in it! That was very extreme, but I'm sure you could easily keep 40 guppies in a 40 gallon tank with no over-crowding.


----------



## Tsin21 (Oct 12, 2017)

hoppycalif said:


> Guppies are so small you can put a lot of them in that size tank. Many years ago I started out with a 10 gallon tank that at one time had almost 100 guppies in it! That was very extreme, but I'm sure you could easily keep 40 guppies in a 40 gallon tank with no over-crowding.


That's great! Thanks!


----------



## Michael (Jul 20, 2010)

The biggest problem with fish like guppies or Endler's is that they reproduce so quickly that even if you start with just one pregnant female, they will eventually over-crowd the tank. So be prepared to thin the population from time to time.


----------



## DutchMuch (Apr 12, 2017)

bleh guppies


----------



## mistergreen (Mar 3, 2007)

You can always split male and female guppies into separate tanks. You can control the birth rate. I'm starting to run into this problem in a 75G!


----------



## dwalstad (Apr 14, 2006)

Separating males and female guppies doesn't help, because the females store sperm and are always pregnant. AND they have babies every 30 days. Some of my big females have 60-100 babies at a shot.

If I had a 42 gal tank, I don't think I would add guppies to it. There are so many other fish that don't overpopulate. 

As a guppy breeder, I have to keep plants potted so that I can easily remove the plants to catch excess baby guppies. It's a bit of work. 

Combing out the babies is essential. I tried adding Bettas to tanks to eat the babies, but the Bettas (both males and females) chew up the adult guppy's fins and sometimes kill them during night maneuvers.


----------



## Tsin21 (Oct 12, 2017)

I got the tank last night. It was smaller than expected, only about 30 gallons. The seller made some error on the measurements.


----------



## Tsin21 (Oct 12, 2017)

Michael said:


> The biggest problem with fish like guppies or Endler's is that they reproduce so quickly that even if you start with just one pregnant female, they will eventually over-crowd the tank. So be prepared to thin the population from time to time.


I started with 6 guppies originally, now I have more than 30 and I already gave away some a few times.



DutchMuch said:


> bleh guppies


But they're my favorite fish. :lalala:



mistergreen said:


> You can always split male and female guppies into separate tanks. You can control the birth rate. I'm starting to run into this problem in a 75G!





dwalstad said:


> Separating males and female guppies doesn't help, because the females store sperm and are always pregnant. AND they have babies every 30 days. Some of my big females have 60-100 babies at a shot.
> 
> If I had a 42 gal tank, I don't think I would add guppies to it. There are so many other fish that don't overpopulate.
> 
> ...


The danios help a bit in the population control.
Thanks for the replies!


----------



## gkai (May 14, 2018)

depending on the type of guppies, you will probaly loose your RCS. They will not eat the adult, but except for very fancy guppies that tends to be slow, they will eat the juveniles, just after hatching or slightly after when they are still very small.

Usually small RCS can hide in mosses or other places not really accesible to fishes, or just be lucky.... but when you have a lot of guppies, including small but hungry juvenile guppies that explore everywhere.

I had a self-reproducing RCS colony in a 80L tank. After introducing guppies, they statrted to reproduce and new generations got both slightly smaller but also more hardy and efficient predator. More varied pattern on the male too, I suspect they got closer to their natural aspect. All very nice, but at the same time my RCS colony slowly dissapeared. I never saw an adult RCS eaten, guppies not even bothered them appart when fighting for food. But I never saw juvenile shrimps anymore either :-/


----------



## Tsin21 (Oct 12, 2017)

gkai said:


> depending on the type of guppies, you will probaly loose your RCS. They will not eat the adult, but except for very fancy guppies that tends to be slow, they will eat the juveniles, just after hatching or slightly after when they are still very small.
> 
> Usually small RCS can hide in mosses or other places not really accesible to fishes, or just be lucky.... but when you have a lot of guppies, including small but hungry juvenile guppies that explore everywhere.
> 
> I had a self-reproducing RCS colony in a 80L tank. After introducing guppies, they statrted to reproduce and new generations got both slightly smaller but also more hardy and efficient predator. More varied pattern on the male too, I suspect they got closer to their natural aspect. All very nice, but at the same time my RCS colony slowly dissapeared. I never saw an adult RCS eaten, guppies not even bothered them appart when fighting for food. But I never saw juvenile shrimps anymore either :-/


Thanks for the insight. I had a similar experience with my shrimp bowl when there was a single guppy fry in there. It never had any shrimplets for two months while the guppy fry was there. After I removed the fry, the shrimp population went up after about a month. On a separate case, the shrimps and guppies are fine in my previous 15 gallon community tank. It might be due to availability of hiding places for the shrimps or just got lucky I guess.


----------



## Tsin21 (Oct 12, 2017)

Finally got it up and running. Will be adding the fishes once the water is clear.


----------



## hoppycalif (Apr 7, 2005)

That looks very good! I like the background lighting. Is that just coincidental or did you do that on purpose?


----------



## Tsin21 (Oct 12, 2017)

Thanks! The background lighting is coincidental from the curtains.


----------



## Tsin21 (Oct 12, 2017)

I installed a spraybar on the powerhead since it was so strong that it uprooted some of the swords and water sprite.
I can see some of the bacopa and elodea are melting.


----------



## dwalstad (Apr 14, 2006)

Tsin21 said:


> I can see some of the bacopa and elodea are melting.


You mean that these two plant species are dying? You may not need that much water circulation. Or you can just run the pump at night.


----------



## Tsin21 (Oct 12, 2017)

dwalstad said:


> Tsin21 said:
> 
> 
> > I can see some of the bacopa and elodea are melting.
> ...


 The spray bar baffled the current just enough for circulation and almost no movements from the plants. I'll try turning it off in the morning and see how it affects the inhabitants. As for the plants, the elodea are mostly dead now, they're actually not in good condition when I bought them. While some of the bacopa are having new growth. Most of the watersprite are uprooted and are damaged so I'm letting them float now until they recovered.


----------



## Tsin21 (Oct 12, 2017)

Here's the latest photo, taken an hour ago.


----------



## kafkabeetle (Oct 11, 2011)

I bet those are some very happy guppies with all that room! I like the way you've laid out the stones and the coincidental wave of light across the background. Nice work


----------



## dwalstad (Apr 14, 2006)

Tsin21 said:


> The spray bar baffled the current just enough for circulation and almost no movements from the plants. I'll try turning it off in the morning and see how it affects the inhabitants. As for the plants, the elodea are mostly dead now, they're actually not in good condition when I bought them. While some of the bacopa are having new growth. Most of the watersprite are uprooted and are damaged so I'm letting them float now until they recovered.


I would keep monitoring rooted plants for new growth. With your nice setup, that Amazon and other rooted plants should be forming new leaves. If not, you may need to poke the substrate a bit to introduce oxygenated water and keep the soil layer from going too anaerobic. Just a temporary measure until the soil layer settles down....

I say this because you are using potting soil and have a fairly deep gravel layer.

How are the guppies doing?


----------



## Michael (Jul 20, 2010)

Don't be afraid to try different species of plants. It's difficult to predict which species will thrive in a particular tank, so trial and error is often necessary.


----------



## Tsin21 (Oct 12, 2017)

kafkabeetle said:


> I bet those are some very happy guppies with all that room! I like the way you've laid out the stones and the coincidental wave of light across the background. Nice work


Thank you! The guppies are exploring every nook and cranny.



dwalstad said:


> I would keep monitoring rooted plants for new growth. With your nice setup, that Amazon and other rooted plants should be forming new leaves. If not, you may need to poke the substrate a bit to introduce oxygenated water and keep the soil layer from going too anaerobic. Just a temporary measure until the soil layer settles down....
> 
> I say this because you are using potting soil and have a fairly deep gravel layer.
> 
> How are the guppies doing?


Thanks! The amazon swords and most of the plants are growing new leaves now. For the soil oxygenation, I've introduced some Malaysian Trumpet Snails though I haven't seen them again; they're are only four and buried most of the time. I might get a few more when they're available again. I also added some ramshorn snails and Devil Lava Snail to help in algae control and eat the dead plant materials. As for the guppies, they are doing great even though the tank is going through a nitrite now. No signs of illness or strange behavior, just ever so hungry. So I added more floating plants and planted a new batch of elodea (which I hope would make it through).

Current tank parameters now:
ph = 7.9
Ammonia = 0
Nitrite = 1mg/l
Nitrates = 50mg/l

Should I do a water change? I'm actually hesitant to do so since I'm reading conflicting answers on different sources. Some say that it might stall the cycle and then some say it will not. So far, the fishes are ok, no flashing and are exhibiting normal behavior. The danios are even spawning.



Michael said:


> Don't be afraid to try different species of plants. It's difficult to predict which species will thrive in a particular tank, so trial and error is often necessary.


I'll pass by the lfs tonight and see what plants I can add.






P.S. sorry the photos are rotated.


----------



## Tsin21 (Oct 12, 2017)

The nitrite spike finally subsided! I actually didn't do any water change, I just added more floating plants and dosed stability. Will be monitoring the parameters further this week.

The guppies are feisty as always and I added some sagittaria & limnophila aromatica (it really smells good!)


----------

