A green freshwater tank is usually a sign of algal bloom inside of the aquarium. Personally, I notice this most in the aquarium that I put outside the house for decorative purposes. Because the tank is exposed adequately with natural sunlight during the day, algae thrived and infested the tank.
The good news is that algal bloom in the tank can be easily removed. Actually, most of the time, it’s just a matter of cleaning the tank, but let’s break it down bit by bit so that you’ll have a few options and some tips you can follow step by step in order to keep your tank as pristine as you want it to be.
First thing: change your fish tank water regularly
Honestly, this advice is something that I also need to practice regularly. I must admit, I can be too lazy sometimes to change water in my fish tanks. And if you’re like me, maybe this is the main reason why your freshwater tank is becoming greener as time goes by.
Basically, you need to change water in your aquarium every other week. Remove about 20% of the water from your aquarium and replace it with fresh water. This activity dilutes the murky water from your tank, and if done religiously, can actually clarify the whole ecosystem of the tank in a few weeks’ time.
Additional to this, when replacing water, try targeting the algae from your tank with a siphon. It’s pretty obvious – less algae left in the tank after replacing the water, the less time it will also take for you to clear the whole tank of the green stuff.
Take note, some algae can also stick to the inside of the aquarium glass and is hard to remove by just a simple siphon. What I do is to scrub the inside of the tank lightly with a clean sponge. Take care of not disturbing the fishes or any plants inside the tank. It just takes a light scrub to scrape sticky algae from the aquarium glass anyway. Then after this, that’s when I siphon some of the water out of my fish tank.
Another good side effect of changing your fish tank water regularly is that it removes nitrates from your tank. Nitrates are the primary food source for algae. That means that if you have a lot of nitrates in your tank, it basically promotes algal bloom and thus, your aquarium can go greener faster as time goes by.
As you can see, it’s pretty much a cycle
Fish waste, leftover fish food and decomposing aquarium plants produce mostly ammonia. Your fish tank filter converts this ammonia into nitrites, and then into nitrates. Nitrates are then eaten up by algae, causing them to bloom. Reducing nitrate levels in your fish tank results to happy fishes. At the same time, it results to less algae, leading to a very happy fish tank owner as well.
As I mentioned earlier, one of the primary sources of ammonia buildup (and eventually nitrate buildup) in the tank is leftover fish food. Pretty obvious when you think about it, that in order to eventually reduce algae is to keep feeding your fish at the minimum level. I feed my fish once every other day. And it’s good practice as well to time how fast your fish consumes the food you give. A good practice is for them to consume food around 1 minute. If you see a lot of food left in the tank after this time, it’s pretty much an indication that you’re over-feeding your fish.
Algae are plant life, and plants need light to survive. Therefore, reducing the light that enters your fish tank can also be a vital component in reducing algal bloom inside. Decrease the lighting in your fish tank to only about 8 hours per day. I believe this is adequate lighting for the fish, and is also good for the fish in the long run. If your fish tank is outdoors, just like some of mine, cover your tank with a cloth to reduce light.
Another good way to reduce algae is to introduce other aquarium plants in your fish tank. The basic premise of this strategy is this – putting more plants in serves as competition for the algae regarding all of the nutrients in the tank meant for them to bloom. It’s like plant versus plant. Larger plants will need more nutrients, and thus, algae will have very left for them to properly survive. Besides, aquarium plants are very beautiful additions to a fish tank. But keep in mind that some fish nibble on these plants as well, so there may be other considerations at play with this strategy.
Keep in mind that all of the strategies that I mentioned here will take some time, probably a few weeks before your aquarium becomes clear of the green stuff. Of course, if you still see a lot of algal bloom in your fish tank even after doing all of the above, then I might have a final suggestion that you can take as a last resort (or a first resort too if you want, it really depends on you). But of course, will take a bit of an investment.
Use an aquarium water clarifier
That’s right, there’s such a product that clarifies your fish tank for you. Why I didn’t suggest this method at first is because when it comes to my own fish tanks, I’m pretty hesitant to introduce other chemicals, and I just go the natural route, although, I have used water clarifiers before with a great degree of success.
Water clarifiers can clear the murky green stuff from your fish tank within hours or days, depending on the product. Generally, water clarifiers are safe for all types of fish. And as an added good side effect, they may also help your filters function more efficiently because aquarium dirt is already treated before filtration. Of course, each product will have its own recommended use, so please before using any of these products, read the instructions thoroughly first. It’s for your fish’s own good.
In conclusion, having a clean, algae-free tank is a result of just that – you need to clean your tank properly. It takes some time and patience, but cleaning is also a pretty easy procedure. It won’t take much of your time, and you get to enjoy your fish tank better as a result. Clarifiers are also available to help you get rid of algal bloom. If you have the extra money and you feel comfortable, I would suggest that you go this route of cleaning as well.