So, you’ve woken up this morning and you’ve discovered that your fish tank is green? The unpleasant appearance of green water may shock you or make you worry for the safety of your fish, but usually it’s nothing too serious and can be fixed quite easily depending on the cause.
In layman’s terms, your fish tank is green because of an algae bloom. Algae is a form of aquatic life found all over the planet and is completely normal to be within your tank. But the problem is when it begins to bloom, it turns the water that nasty green colour that plenty of fish tank enthusiasts are very familiar with.
What is causing it?
There are usually three things that can be causing your fish tank to look green, and this isn’t in any order but try altering one thing before altering the next so you can find the root cause of the problem.
To many fish
The fish keeper’s worst nightmare, maybe you have calculated slightly wrong or haven’t properly realised how many fish you can have in your tank. If you have to many fish, they produce too much waste that gives the algae to much food and just begins to bloom.
This is quite an easy fix, just don’t feed them as much! But we will get into more detail about this later in the article but simply what happens is, you put too much food in that doesn’t get eat so the algae take the nutrients from the remaining left-over food and blooms.
Too much light
If you leave the light on all the time, Algae absolutely loves light and creates energy for itself through a process called photosynthesis causing it to bloom. It may even be sunlight.
How to fix it?
To many fish
You may have to remove some of your fish. Ensure to read a guide on how many fish you can stock in your tank. Remove your fish and see how the eco system balances itself out after a week or so. You might find that the system comes back into balance and your green water begins to go clear again.
An easy way to see how much you need to feed your fish is by putting a pinch in and seeing if it is all consumed within five minutes, if you watch a lot of it sinking to the bottom of the tank then you may be overfeeding them, slight amounts should fall to the bottom but not a large amount.
Too much light
This one can be a little difficult, but it is fixable, you may need to get some sort of auto lighting system or even block out the sun from outside, I will cover this in detail a little later.
So, you can fix it in other ways, you could introduce daphnia to the system, but they will be eventually eaten by the fish. Snails or shrimp are also a great option.
How to prevent it?
- Ensure you change your water regularly.
- Ensure you clean your aquarium regularly.
- Use a UV filter – Click here for our recommended UV filter.
- Use an automatic feeder system – Click here for our recommended feeder.
- Use a diatomic filter.