What Causes Micro Bubbles In Aquarium – (3 Easy Fixes)

What causes micro bubbles aquarium

Nobody likes Micro Bubbles! Because they can make your tank look dirty or cloudy when it really isn’t. But what causes micro bubbles in aquarium?

Most of the time it’s your filter causing these bubbles. So I’m going to share with you 3 very easy ways of how to stop those micro bubbles right now. So easy you might smack yourself for not thinking of it sooner. We’ll also go over different types and other reasons for micro bubbles not caused by your filter later in the article.



1- Micro Bubbles from unsealed canister filter

First thing we need to check is going to be very obvious but I understand, it happens. An improperly sealed canister filter can be what causes micro bubbles in aquarium.

All Canister tops come with a gasket, which is what prevents any leaks. Leaks from water coming out and air getting in.  So make sure its installed and installed correctly on your canister cover. Then make sure that the top is tightened correctly.

FX6 Gasket

On a Fluval FX6 don’t over tighten these locks but make sure they’re pretty snug. And you’ll want to tighten them using a cross pattern to make sure all sides of the top are sealed.

On a Fluval 07 series or similar canister I would push down on the top while installing to make sure its seated properly.

If you’re top isn’t properly sealed it will suck in air and then spit that air out from your outputs creating micro bubbles in the tank.


2 – Hose connection causing Micro Bubbles

Your hose connections must be fully submerged in the water. These connections are not air tight.

FLuval 07 hose connection

You can easily disconnect or reconnect them, which means air can and will easily get in through here. This will definitely cause micro bubbles spitting out of your output. The only way to prevent air from getting into these connections is to make sure they’re fully submerged.


3 – Micro bubbles through your filter intakes

Last very easy, but commonly missed fix is your air stone or bubbler being to close to your intake.

If your purposely made bubbles are to close to a filter intake they can get sucked right into the intake. And then they’ll go through your filter and get spit out the output as micro bubbles.

Obviously this is a very easy fix right, just move your bubbler or your intake so the bubbles don’t get sucked in, but many people don’t realize this is even happening.


Other causes for micro bubbles in aquarium

Temperature Changes

There are other types of micro bubbles that can be in your tank that have nothing to do with your filter. A very common one is micro bubbles stuck to your glass or on your décor. This usually happens after a water change and is caused by a difference in water temperature.

What causes micro bubbles in aquarium

Colder water holds more oxygen than warmer water. So if you added colder water to your tank than the water currently in there you’ll get these micro bubbles all over your glass.

Now the bubbles themselves don’t do any harm and they’ll go away on their own once the temperature stabilizes but this is an indication that you’re adding water at a very different temperature than your tank. This can shock your fish and be very harmful to them. So if you see these bubbles after a water change keep a close eye on your fish for any signs of stress. There isn’t much you can do at this point if your fish are in a temperature shock except to learn from it for the next water change.

Removing the fish into another tank with warmer water will only shock them more because of well…temperature change, again.


Dirty Tank

Another common type of micro bubbles are those that stay stuck at your surface and never pop. The main reason for this is that your tank is dirty.

Have you ever seen a dusty, oily film at your surface. Well dirt from your tank that shouldn’t be in your tank will rise and collect at the surface. You may have added new substrate or a new piece of décor and didn’t rinse them properly. Now whatever dust or dirt that was on them is in your tank.

That dust and dirt traps the bubbles and doesn’t allow them to pop. Your water might also be oily, either form some bad quality products you used, bad quality food you’re feeding or even worse maybe some soap or a detergent got into your tank. This oily surface also wont allow for the bubbles to pop.

So in this case, if you suspect it’s the food or some products you’re using stop using them…easy right. To get your tank clean again start with a nice big water change. You wont get all the dirt, dust , or oil out in just 1 water change, but overtime and multiple water changes you’ll get that stuff preventing your bubbles from popping, out of your tank.


Trouble with getting Crystal Clear Water?

Many beginners in the hobby have a rough time getting and keeping their tanks looking crystal clear. It’s understandable because new tank setups are going through a process that can cause cloudy water. (Bacterial Bloom) That, as well as not knowing everything you should about your tank and how to keep it clean is just a double whammy! Start Here and you’ll have crystal clear water in no time!

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About Me

“I don’t want my fish to survive, I want them to THRIVE!”

I’ve had a passion for aquariums ever since my first Goldfish in a bowl! Through years of experience I’ve learned how to care and provide for my fish, spoiling them along the way! The joy of this hobby comes from knowing my fish are happy and healthy, growing and thriving. 

I’ve also learned that I have the ability to help others with their tanks and fish…and I’m happy to help! Welcome to the Site, hopefully you’ll find a topic that can guide you in your fish keeping journey. Thanks for visiting!

KaveMan Aquatics

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