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How Fast Do Blue Tangs Grow In An Aquarium?

Blue tang are one of the more popular marine fish that are commonly kept by fish keepers of all levels of experience with many beginners to the hobby being drawn to the species due to their beautiful colors and patterns.

This does however often raise a number of questions, especially from people new to keeping tang and although we have already covered a number of the commonly asked questions that we see, we have noticed a spike in the number of people asking how fast blue tangs grow recently so wanted to publish this article.

A healthy blue tang that is kept in a suitably sized tank and fed an optimal diet should grow at a rate of around two inches per year for the first few years of their life.

Their growth rate will naturally slow to around once inch per year until they reach maximum length after the initial few years of their life with 12 inches usually being the maximum blue tang length.

If you are looking for a small tang species that will remain small for your tank then our article going over six of the smallest tang species may be helpful for you. When it comes to promoting a healthy growth rate for your blue tangs, a a suitable fish food is essential and will ensure optimal growth of your fish.

The majority of fish foods on the market are designed for omnivores and are far from optimal for your blue tang who is a herbivore so getting a specific food product for your tang can be a great investment if your tank has a large number of algae eaters in it.

How Fast Do Blue Tangs Grow In An Aquarium?

A blue tang with a suitable diet should grow at a rate of two inches per year for the first two to three years of its life before its growth rate slows to one inch per year.

The majority of blue tang will then stick to this one inch of growth per year rate until they reach a maximum length of around twelve inches and their growth stops.

We have seen a number of people suggest that the size of your aquarium will play a role in how large your blue tang will grow but this is not correct.

Your blue tangs growth rate is based on its genetics and its body will try to grow to a maximum length of around twelve inches no matter its tank size or diet.

Although a a suitable fish food can promote healthy growth at a steady pace, a blue tang will still grow to around twelve inches in length on a poor diet, it just takes longer.

There are two main strategies for keeping blue tang in captivity when it comes to their tank size. Some people will upgrade the tanks of their blue tang every couple of years as they grow but this is a less common strategy that we usually recommend against.

The more common and more cost-effective strategy overall is to simply get a tank that is around 100 gallons or larger and suitable for adult blue tang and just let your fish grow in the tank until they reach their maximum length.

How Long Does It Take for A Blue Tang To Reach Full Size?

The rate of growth of blue tang depends largely on their diet with a blue tang on a suitable diet being able to reach its full size in as little as five years in some situations.

A blue tang kept on a poor diet can take as long as ten years to reach its full size though due to poor nutrition stunting the growth rate of the fish.

A large number of people who are new to keeping blue tang seem to presume that they are omnivores and feed them a regular fish food.

This is not correct as blue tang are herbivores and a fish food for omnivores will end up in a nutritional deficit and a slower growth rate due to the fish not being able to get all of the vitamins and minerals that it requires from the meat based parts of a food designed for omnivores.

You will often find your blue tang feeding on algae, detritus, and bio film in your tank and some people presume that this will provide all of the food that your blue tang requires.

Again, this is not correct and although the majority of blue tang will forage for food most of their day, the majority of tanks, especially those with other algae eaters in it are simply not able to provide all the calories required for optimal growth in a blue tang.

This is why we always recommend that our readers do their best to supplement the diets of their blue tang with a a suitable fish food or something like seaweed sheets to help promote healthy growth for your fish.

How Big Do Blue Tang Fish Grow In An Aquarium?

The majority of blue tang will grow to a maximum length of around twelve inches when fully grown adults but in rare situations, some blue tang can get as long as fifteen inches.

Keep in mind that blue tang have two growth stages with their growth rate being rapid for the first few years of their life before gradually slowing with some people presuming their blue tang has finished growing once its growth rate stops.

As we have covered above, even after the growth rate of your blue tang slows to a growth rate of one inch per year or less, the majority of blue tang will still continue to grow until they get to around the twelve inch in length mark.

We know that their growth rate can slow drastically if they are not provided with a suitable diet with some tang growing less than a quarter of an inch per year if they are on a nutritionally deficient diet but the fish will keep growing.

In some very rare situations, some people may end up with a totally different fish species altogether as there are some fish that can look similar to a blue tang but aren’t.

This is not as common as it was back in 2016/2017 when the Finding Dori movie was released and the demand for blue tang drastically increased but we have seen it happen on occasion.

This can take some fish keepers by surprise as the fish they thought was a blue tang can have a totally different growth rate and maximum length.


That brings our article going over how fast blue tangs grow to an end and we hope that we have been able to help you. We have tried to cover all of the common mistakes that we see people making who are looking to keep blue tang as well as explain why your blue tangs growth rate may change. The initial slow down of growth in blue tang is totally normal and to be expected but a poor diet in blue tang is common and is usually a very quick, easy, and cheap fix.