If you have discovered tiny bugs in your fish tank, you may (understandably) be worried.
Fortunately, the bugs are probably water mites, and most species are harmless.
Still, having mites in your aquarium could signal that something else is wrong, and water mite populations can get out of control quickly.
What Do Water Mites Look Like?
Some water mites look like tiny aquatic spiders. They have four pairs of legs, a round, unsegmented body, and a very small head.
Others look like miniature shrimp or small floating crystals.
From far away, water mites may appear as black or white specks. They may appear in your aquarium plants, or you may see them floating around your tank.
Most of the time, you will not notice water mites unless there is a serious infestation.
Are Water Mites Harmful?
There are more than 5,000 species of water mites, and they exist in almost every aquatic ecosystem.
Some water mites, such as the parasitic Acariformes, are harmful, but most are not.
The most common water mites in fish tanks include:
While some water mites are parasitic and prey on small fish, most of the water mites above will be a tasty snack for your fishy friends.
In fact, daphnia is one of the regal betta fish’s favorite treats.
Of course, mite populations can spiral out of control and cause serious problems for aquarium owners, especially those with closed aquarium systems.
For example, water mites can change your water’s pH, remove too much oxygen from the water, harm your aquatic plants, and carry diseases.
Too many mites can also crawl on your fish and irritate their skin, and some mites are parasitic.
Water mites can also create quite the eyesore in your aquarium, so we understand why you would want to get rid of them!
How Do I Get Rid of Mites in My Aquarium?
Water mites often come from fish or plants you introduce to your tank, and they thrive when your tank is not clean.
This is why cleaning and maintaining your tank regularly is important — as well as quarantining new fish before introducing them to your aquarium.
Though the best way to get rid of water mites is to prevent them from invading your tank in the first place, you can clean your tank to get rid of water mites after the fact. Change up to 30% of your water and vacuum your substrate carefully.
Most mites feed on algae, so when you reduce the number of algae in your tank, most of the mites will die off.
You can also introduce tank mates that will happily feed on water mites, such as shrimp or small, bottom-dwelling crabs. Cleaner species like shrimp can also help you keep your tank clean overall.
Please know that getting rid of water mites is extremely difficult, and there will probably be some leftover — even with your best cleaning efforts.
Don’t worry though, harmless water mites are an important part of healthy marine ecosystems.
Many fishkeepers are pleased to see a small population of copepods and amphipods living in their aquariums.
After all, the more your tank mirrors your fish’s natural habitat, the more easily your tank goes through natural cycles, and the healthier and happier your fish will be.
Don’t Forget To Check Your Water Parameters
If you notice lots of water mites in your fish tank, be sure to check your water parameters.
A large mite population could indicate high levels of harmful bacteria or be a warning that something is going wrong in your tank.
Remember that ammonia and nitrites must be well below 1ppm (as close to 0ppm as possible), and nitrates should always be below 20ppm.
Water mites may not be a huge problem in and of themselves, but they could be a warning that something is seriously wrong.
How Do You Treat Water Mites?
Most mites can be left alone or reduced with a deep clean.
Nevertheless, if you are dealing with parasitic mites in your aquarium, you will need to treat your entire tank for parasites.
Fish that rub themselves on aquarium decorations, gasp for air at the water’s surface, or act aggravated or restless are telltale signs of a parasite infestation.
To treat your fish for lice, you must physically remove the parasite and treat the wound with iodine — or bathe your fish regularly in a saltwater or formalin bath.
Treating Gill Mites
To treat your fish for gill mites or other parasites, add medicinal tablets to the water and carry out a multi-day treatment.
You can buy parasite medicines at pet stores or online.
So, What Do I Do About Water Mites in My Fish Tank?
If you see water mites in your fish tank, do not panic.
Give your aquarium a deep clean; the mites should go away on their own. For extra help, consider adding shrimp or crabs to your tank.
Don’t forget to check your water parameters while you’re cleaning.
Water mites thrive in tanks with poor water quality, and you need to keep ammonia, nitrite, and nitrate levels down to protect your fish. You also need to ensure your tank water is clean.
Because water mites are hard to eliminate, you can also focus on prevention instead.
Never introduce a new fish or aquatic plant without a quarantine period, and perform partial water changes (and substrate vacuuming) every 7-10 days to keep algae and bacteria under control.
If you notice that your fish is itchy or irritated, you might have a species of parasitic water mite on your hands. Clean your tank as described above, then consider an appropriate parasite treatment if the problem is not resolved.
Remember, most water mites are nothing to worry about, but it’s always good to clean your tank and check water parameters when in doubt.
Also, don’t hesitate to call a veterinarian or tend to your fish with over-the-counter medicines if it seems sick or irritated.