While most types of algae are pretty harmless to fish, and may even be a food source for some, if left unchecked it can become very unsightly. So here are some of the most common types of algae you may find in your aquarium, and what you can do to get rid of it.
If your tank has a dusty dirty brown look to it, you may be dealing with diatom algae and it can leave your aquarium looking really filthy. Diatom algae typically is found in newly started aquariums and often times this may indicate that you have high phosphates in your aquarium. Now this type of algae can tend to grow pretty quickly in a tank so to get rid of diatom algae you're going to want to make sure that you wipe all the sides of the tank, and take care of cleaning any ornaments before you do your gravel vacuuming. Basically, you're going be wanting to remove as much of the diatom algae as possible from the aquarium.
Green Hair Algae
Green hair algae can be a nightmare to get rid of and get under control. This one is found quite commonly in planted aquariums and if not dealt with can potentially outcompete your plants. Now this type of algae usually forms little clumps of hair like threads throughout the tank wall. It's not hard to remove the hair algae that you find in the tank you really have to get rid of the root cause or you will continue to find more and more hair algae in the tank.
Now this one is a little bit more complicated when you're trying to deal with it, because it's kind of a balancing act. The biggest reason why this will typically appear in your planted aquarium is that you don't have a balance of how long you're running your lights and how much co2 you are dosing the tank with. So basically, what you're going to have to do is figure out how long you can run your lights and how much co2 you should be dosing. You will want to also be careful not to overdose the co2 in your tank because you could lose your fish.
Now every tank is different, some people have more plants than others and some plants require higher lighting and things like that so it can be a bit of trial and error. I know I personally run my tank lights about six to eight hours a day, any more than eight hours a day and I end up with some form of algae. So, you might have to do a little bit of research on how much co2 and how long you need to run your lights for the specific plants that you keep and your tank size. But typically if you are seeing this type of algae in your tank scrubbing down your tank and then doing a good water change, along with cutting back on how long you're running your lights for, and possibly upping your co2 dosage should help get this algae problem under control.
Green Water Algae
You wake up in the morning and find the water in your tank has turned green! This is a floating type of algae that is actually a single-celled form of algae which can spread through your tank like wildfire.
Now this type of algae is typically found in tanks with low circulation or low-flow filters, so if you do have fish that can handle higher flow filtration or upping the circulation in the tank, then by all means either turn the flow up or get a higher power filter.
Adding a skimmer to your tank can usually help to resolve this along with adding UV sterilizers. Now barring that doing additional water changes and cutting back on how much you're feeding your fish usually will help resolve this.
Green Spot Algae
This is usually seen as a dark green colored algae that tends to hang around on your glass and possibly some of your ornaments. This type of algae tends to be a little bit harder to scrub off, and a lot of times you will have to use some type of bladed scraper. If you have an acrylic tank you will need to be very careful if you use a scraper as they can scratch very easily. So, if you are cleaning an acrylic tank you will probably want to use a plastic bladed scraper.
Now typically this type of algae is more of a light issue so cutting back on how long you are running your lights, along with doing a couple additional water changes should usually help you out with getting rid of it.
Green Dust Algae
If you find yourself scrubbing the algae off the glass in your tank, only to have it all reappear an hour or so later, you might have green dust algae. This is actually a free-swimming type of algae, so basically when you wipe it down it’s swimming in your tank, and then it will settle back on the walls and ornaments in the tank. Often with this type of algae, aquarists will let the algae settle and grow so that it can completely be removed from the tank. Unfortunately, this means you would have to deal with an ugly tank for a few weeks before being able to scrape it off and permanently remove it from your tank.
Black Beard Algae
This type of algae tends to grow in dark patches on ornaments and your filtration. To remove black algae from your tank you will have to take out all your ornaments and any equipment that it has formed on and bleach them before re adding them back to the tank.
Just as the name would imply, this is algae that you're going to find floating at the top of your tank. Now adding a skimmer to the tank can help to get rid of that problem pretty quickly. This is a common problem in tanks with low filtration or low water circulation, so if you do have fish that can deal with higher filtration and higher water flow, then you can switch out your filter or up the flow of your filter in the tank. If that is not an option, doing more frequent water changes can help to eliminate this type of algae.
Tips for Algae Control
If you hate scrubbing there are natural ways to help keep your tank algae free, or at least keep algae from getting out of control in your aquarium. Often algae is caused from running your lights for too long, nitrates being too high, or having too little CO2 in your tank.
Adding live plants to your aquarium can really help to cut down on nitrates helping to prevent algae from being able to grow in the first place. Algae eating fish, shrimp, or snails can also make a wonderful addition to your aquarium that will help to keep algae under control.
Now not all algae eaters are created equally and some of them can get huge, so you will want to make sure that if you do pick out an algae eater, you pick one that helps with the types of algae that you keep encountering as well as not growing to be too big for your aquarium. You want to also take care to find the algae eater that is right for the job. When it comes to hair or brush algae though, amano shrimp, Siamese algae eaters, or flag fish are some of the few species that will feed on them.