Why Is There Hair Algae in Low Phosphate Conditions?

Getting a low phosphate reading in your aquarium tank when there are hair algae growing can be confusing considering algae need phosphate to grow.

However, the reason why you would have a low phosphate reading is that reflects the environmental conditions after the algae have consumed all the phosphate.

Additionally, some water tests cannot detect all of the available forms of phosphate so it may not be a completely accurate reading.

In this article, we will cover whether or not hair algae can grow without phosphate, if high phosphate causes hair algae, and what other nutrients may cause hair algae.

Can Hair Algae Grow Without Phosphate?

Hair algae cannot grow without phosphate. All algae need phosphate in order to grow and thrive. Phosphate is produced by the waste products of fish and any dead material from plants or animals that sink to the bottom of the tank.

Without these available sources of phosphate, hair algae would not be able to sustain the growth and reproduction they need to accomplish in order to completely take over an aquarium tank.

Hair Algae in Low Phosphate Conditions

Does High Phosphate Cause Hair Algae?

An overabundance of phosphate can cause hair algae to increase its population exponentially. It may not be the initial cause of hair algae introduction into an aquarium tank, but it will cause it to grow and reproduce at a rapid rate.

Phosphate is an essential nutrient for hair algae. The less maintenance you perform in your aquarium tank, the more phosphate there is from dead plant and animal material and waste products to feed the hair algae.

It’s important to regularly clean your tank or have algae eating fish or invertebrates to maintain a healthy environment for all of your reef tank’s inhabitants. That way you won’t have a tank overrun by hair algae.

What Nutrients Cause Hair Algae?

Having too much nutrients in your tank’s water can cause hair algae to proliferate. Iron is especially important to keep under control. The hair algae can use an overabundance of iron to enhance their growth and spread throughout the tank.

Low levels of other nutrients can also be the cause of hair algae in your aquarium tank. Carbon dioxide and nitrate found in low concentrations can encourage the growth of hair algae.

By increasing the carbon dioxide in the system, you will provide beneficial nutrients for your aquarium plants instead of the hair algae.

However, one of the biggest causes of hair algae in your tank is an overabundance of light. Too much light can encourage hair algae to grow and grow fast. Be particularly wary of this when you install a new aquarium light because it will extremely strong.

You may be used to having your light on for a certain period of time during the day, but it may be wise to cut it back if you get a new light. Otherwise, you will most likely have a hair algae in your hands and in your tank.


Hello, I'm Jason. I'm the guy behind HelpUsFish.com. I volunteer at my local fish shop and I created this site to offer tips and advice on the fish I care for.

Recent Posts