• Skip to main content
  • Skip to primary sidebar
  • Home
  • Bettas 101
    • Acclimation
    • All About Water
      • Nitrogen Cycle
      • Ph & Ammonia
      • Water Changes
    • Betta Fish Anatomy
    • Betta Vases
    • Choosing a Tank
    • Feeding Bettas
      • Food Myths
      • Frozen & Live Betta Food
    • Tankmates for Bettas
      • African Dwarf Frogs & Bettas
      • Apple Snails & Bettas
      • Neon Tetras & Bettas
      • Otocinclus Catfish & Bettas
      • Quarantine New Fish
    • Plakat Betta
    • Rosetail Betta
    • Veil-tail Betta
  • Sick Betta
    • Diseases and Treatment
    • Aging Bettas
    • Bloating and Constipation
    • Cotton Wool Disease
    • Dropsy
    • Fin Rot and Fin Loss
    • First Steps
    • Gill Hyperplasia
    • Ich
    • Popeye
    • Septicemia (Infection)
    • Swim Bladder Disorder
    • Sick Betta Symptom Checker
    • Velvet Disease
    • Wounded Betta
    • Fish Tank Granuloma
  • Behavior
    • Bubble Nests
    • Skittish Bettas
    • Tail Biting
  • Breeding Bettas
  • Equipment
  • Q & A
  • Other fish
  • Contact

Fish Care

Everything You Need to Know About Betta Fish

You are here: Home / Behavior / Distilled Water May Cause Lethargy in Bettas

Distilled Water May Cause Lethargy in Bettas


Q: HO wrote,

Hello there. I have had my betta for about 6 months in a 1 gallon bowl. I heard that bettas are supposed to be pretty active but mine mostly just lays on his plant. He doesn’t greet me with a wiggle like other people say their bettas do. I tested for ammonia like you said and it was zero. I change his water every 4 days with bottled distilled water. I also noticed his color isn’t as bright as it used to be.

A: The cause of betta lethargy can be difficult to pinpoint because there are so many environmental factors that affect them. What stood out to me immediately is that you are keeping him in pure distilled water. Unlike tap water or spring water, distilled water has gone through a process that strips it almost completely of all minerals. Like RO water (reverse osmosis), it is essentially pure and no longer contains any of the trace elements that would be found naturally in water. Fish kept in distilled water over a period of time may show signs of lethargy or color loss like you described. Most aquarists choose to use tap water because it is very inexpensive and if treated with a good aquarium conditioner is safer and healthier for your fish then distilled. If you have tested your tap water and found that it isn’t suitable for fish (extremely high or low pH for example) you could buy bottled spring water. Spring water has not gone through the distilling process and still contains the minerals bettas need. It is considerably more expensive then tap water but usually less expensive then the distilled water you are currently buying.

Temperature fluctuations may have also contributed to your bettas lack of energy. An small unheated bowl can fluctuate several degrees from day to night. I find that a 2.5 gallon tank with a 7.5 watt heater or a 5 gallon with a 25 watt heater will hold the tank stable so the temperature isn’t able to drop at night. Because they are cold blooded animals, bettas can become lethargic very quickly when temperatures fall. When the temperatures fluctuate several degrees over a short time bettas can become stressed, slow down, loose color and even become quite sick.


Filed Under: Behavior, Sluggish Betta

Reader Interactions

Leave a Reply Cancel reply

Your email address will not be published. Required fields are marked *

Primary Sidebar

Search


Recent Posts

  • Cool Betta Fish Tank Ideas
  • How Long Do Betta Fish Live For? – 5 Helpful Tips For a Long and Happy Life
  • 3 Gallon Fish Tank for Betta
  • 10 Gallon Aquarium Stands and Cabinets
  • How Much Do Betta Fish Cost to Buy and Care For?

NippyFish Facebook Page

Visit the NippyFish Facebook Page

Featured Posts

Complete Guide to Betta Fish Diseases and Treatment

This complete guide on Betta fish illnesses and diseases from A-Z will help you pinpoint what is wrong with your Betta and how to treat it.

The 4 Most Common Signs of Illness in Betta Fish

This article focuses on the 4 most common signs of illness in Betta fish.

Betta Fish Tank Setup – A Detailed Guide For Beginners

This article will be providing a detailed beginners guide on how to setup a tank for your Betta fish.

Top 12 Betta Fish Toys

This article has a list of some of our favorite Betta fish toys. Don’t have a bored Betta.

Setup an Aquatic Plant Environment For Your Betta

Having a healthy plant in your tank will help to improve the water quality by filtering out waste and removing some of the CO2 that’s produced by your fish.

Copyright © 2025 All Rights Reserved | NippyFish | Privacy Policy

Nippyfish.net is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to amazon.com.