[christinamac]

There are many recommendations and guidelines out there when it comes to choosing the right tank size for your fish (or choosing fish for your tank size). For example, a minimum of 2.5 gallons is recommended for one Betta fish.

Are these recommendations pointing more towards tank size (as in square footage or dimensions) or towards the net water volume (the amount of water the aquarium actually contains after adding gravel, etc.)?

The aquarium I have for my Betta can hold 2.5 gallons if there is nothing in it but water. But due to water displacement after adding gravel and decor, the net water volume in my aquarium is about 1.9 gallons. So my Betta has about 2.5 gallons of aquarium room to swim in, but technically only 1.9 gallons of water.

Which do you think is more important?

 

[LittleStar]

This goes along with the often misunderstood one inch of fish per one gallon of water (confusing because you can't keep an Oscar in a ten gallon tank).

I dunno, I think the more water volume the better. It allows more oxygen and beneficial bacteria and you should try to ensure the water volume isn't taken away too much by the décor (or upsize the tank).

I have bare bottom tanks, little décor, and as a result no problems at all housing three small occupants in a 5.5G. They are happy and healthy.

Tank 1: Betta Girl + Platy Boy
Tank 2: Molly, Platy and Guppy all girls
Tank 3: Molly Girl and Platy Boy

Video https://youtu.be/y2BfCsktjBI

 

[christinamac]

I check my water parameters often and they are always great. I perform at least a 50% partial water change at the end of the week and an additional 5-10% water change in the middle of the week. So my Betta is not lacking in fresh, clean water.

The 1 gallon per inch of fish rule does come to mind (not a good rule). Since 2.5 gallons is the minimum recommended size for 1 Betta, and that is the size tank I have, I think I am okay in my situation. But you're right, bigger is always better when it comes to tank size.

 

[LittleStar]

Well from what I have read in the forum your tank rocks and you are an excellent fish keeper so you'll do just fine I'm sure : )

 

[christinamac]

Well from what I have read in the forum your tank rocks and you are an excellent fish keeper so you'll do just fine I'm sure : )

Awww, thank you! :-D

 

[RussellTheShihTzu]

Published gallons are calculated by outside measurements; Kritter Keepers' even include the lid. I've never had a problem keeping Betta in a 2.5; I just prefer the 5.5 because I can do more planting, etc., with it.

Check this site:

http://www.saltyzoo.com/SaltyCalcs/TankSetupCalc.php

Edit: The "One Inch" rule came about in the 1920s when there was no filtration and people didn't keep larger fish. Mostly Goldfish which didn't survive to get full size.