Betta Tank & Questions

June FOTM Photo Contest Starts Now! Fish of the Month
🏆 Click to enter! 🏆


Fish Fanatic
Jul 25, 2021
Reaction score
I've come to the decision to turn my 4.2 Gallon spare tank into a Betta tank. This was thought up last week, and I've finally got the tank set up and the betta on the way. The tank was cycled for about 6 weeks before I tore it apart yesterday and reset the whole thing, though the sponge filter has been in use for months beforehand in this tank previously and my sister's axolotl tank so still has beneficial bacteria. The hardscape and plants were previously in my other tank too. Here is a photo of the tank completed:
Betta Tank.jpg

Plants include Java Fern, Water Wisteria, Blue Stricta, Flame Moss and Giant Duckweed. Would more cover be required for a betta? I have plenty more water wisteria if so that could work for a (temporary) solution. Also, the tank looks small as the dimensions are pretty strange, but it is much deeper on the other side so there is more floor space than you think. I can provide more photos if anybody wants, though chances are I'll end up re-arranging it anyways.

Onto the betta, this is my first time owning a betta so I wanted to make sure I got the right information if somebody can confirm.
Temperature: set to 26 degrees Celsius (78.8 Fahrenheit)
Food: currently Nutrafin Max Tropical Micro Fish Pellets with occasional frozen community food (mixture)
pH: 7.5 (may be lower with driftwood tannins)
I'm sure there's more but that's all I can think of for now, along with ammonia, nitrate and nitrite levels all of which I will measure in the morning.

This is the betta that I bought online (from a reputable Australian betta-focused online store with quality, healthy fish) -
It's a female Fancy Crowntail which I suspect to be only 3 months old due to the short tail and fry-like body shape and colours. Wasn't gonna go for her, but I decided to take the risk. Is anybody able to tell if she will grow in size or if her body will colour up?

Sorry for the long post, any help and opinions are appreciated, thanks in advance.
Hey :)
4.2 gal is very small...
If you tore the substrate you could face a new nitrogen cycle : bacterias dislike being messed up.

26°C ✅

Food ☹️Betta is mainly carnivorous and prefers at least frozen food or high quality food like OmegaOne Betta Buffet or Fluval Betta BugBites, food made with "whole" ingredients, not with "meals" ingredients. Vary food is also important to fish.

pH 7.5 ❌ Betta needs pH 6 to 7 and GH (hardness) KH (alkalinity) < below 6
NO amonnia, no nitrites, no nitrates.

Slow flow.
No tank mate.
Weekly water change of the same temp. and parameters as tank.

➡️ much more plants, including floating ones ⬅️

Also, you should know that "fancy" Betta carries the marble gene that will make colours and patterns change/modifies between 6-8 months to 12-15 months old.

This, if you want to make sure you get the right information ;)
Last edited:
Looks good to me, though you could probably do with a couple more plants in my opinion. Bettas are super fun. Enjoy!
As the others have said, lots more plants, and floating ones that the Betta can rest on near the surface. I’d also do the “tights test” (pantyhose) on any of the hard scaping/wood. If the tights, when stretched over your hand, snag go any part of the wood or rocks then they will be sharp enough to tear the Betta’s fins.
Thanks @Avel1896, regarding the pH, many sources have stated that bettas can do well in a pH up to 8 as long as it is stable and has frequent water changes as higher pH makes toxins more dangerous. Tank size should be an absolute minimum of 3 Gallons, with a recommended of 5+, however 4.2 does beat the minimum and will have frequent water changes to maintain water chemistry. I really can't find any bigger floating plants like frogbit, red root floaters or water lettuce at the moment so I have moved more giant duckweed in temporarily and am floating some water wisteria in the meantime. I've planted some more in the tank too, but it grows insanely fast in my tanks which I can't tell if that is a good or bad thing so it'll be overgrown in no time. I'm planning to go down to a huge aquarium store in two weeks time where I will find some more suitable plants hopefully, but will duck into the pet shop in the morning for some proper betta food. GH is 5.5 as taken from my local water supplier, bubble filter for low flow as they were recommended, no tank mates of course. Thanks for the advice everybody.
It's up to you :) but you should keep in mind that extrem parameters aren't good for fishes. What is tolerated is totally different of what makes a fish thrives.
I kept my Betta CT 7 years in pH 6 to 6.5 / GH KH 4 to 6. Just saying...
Hi :) Congrats on the new betta.

Note though growing beneficial bacteria in an empty tank waiting for fish requires an ammonia source for the bacteria to feed. So keeping a filter on in an empty tank will not grow anything if you don't put maybe fish food to rot etc. But yeah since you are using the sponge from the axolotl tank, then that hopefully has bacteria.

Also buy a bottled bacterial supplement to be sure and treat throughout the first week of the fish to help the biofilter to be boosted.
Also have seachem prime on hand as that instantly binds to ammonia and nitrite for 24-48 hours without making it inaccessible to bacteria to feed on. So you can check the parameters when the fish arrive and adjust accordingly, while your biofilter finds the equilibrium to your biological load.

Hope that made sense.
Thank you, I have dosed with beneficial bacteria and did put some fish food in towards the beginning of the cycle, and water parameters are closely monitored. For now though, everything is running smoothly which is a good sign. I've attached a photo of her in her tank, the wisteria is only temporary until the live plants are shipped out next Monday. Thank you for the advice everybody :) It's really nice to have such a welcoming community always willing to help without putting others down, so thank you.


  • Betta Tank 1.jpg
    Betta Tank 1.jpg
    324 KB · Views: 58
  • Betta Fish.jpg
    Betta Fish.jpg
    174.3 KB · Views: 58
Is there a reason you don't fill up the tank to the top? I always think the more water the better, but I realize there are reasons not to do that sometimes.
Is there a reason you don't fill up the tank to the top? I always think the more water the better, but I realize there are reasons not to do that sometimes
it gets messy when the tank is full from equipment splashes and whatnot. and if you have a lid-less tank fish are more likely to take their last jump if you know what I mean.
This looks great!
I always have to agree more plants more plants more plants.

Okay now that you know how I feel about plants. 🥳😂😃...

Please put your fingers around and under the heater between the wood all around the inside of the tank and see if there's some place your Betta make it stuck if it gets scared especially during water changes or bright lights loud music anything that could frighten your betta could cause the fish to try to flee and hide and possibly get stuck and then not be able to get free, or if it is able to get free it could have damaged that could lead to a bacterial infection.

Just a heads up ...

Gorgeous fishy 🥰
Thank you guys, I usually fill the tank to about 2cm from the top but the water tends to evaporate quickly due to hot weather and high humidity in Australia. There is a lid on the top with 2 corners cut out for power cords as well, but I have not had any issues with jumping. @vanalisa I will check that, thank you, but I did take care to press equipment to the sides and keep hardscape away from the sides where possible. Any gaps between the equipment and hardscape to the sides have an increased distance to prevent her getting stuck. More live plants coming soon, of course.

Most reactions