Algae!!!!

Hey guys! I've an outdoor aquarium which constantly is green. If there is anything known as green water tanks then I have hit the nail on the head. I do massive water changes and then I cover the tank with a cloth and yet in just one week its green again. Help!! ive got 2 goldfish and its a 20 gallon aquarium

 

Hi.

Firstly I like the idea of an outdoor aquarium but direct sun is going to be an issue for green water.

Could you create a more permanent shade structure over it? Only option I know for guaranteed clear water in ponds is a uv light in your filter...if you are running a filter?

Next I hate to say but a 20 gallon is a little small for 2 goldfish long term.

Large water changes sound good, is the tank cycled?

 

Hi KianMan,
I believe you will always have this issue with two goldfish in a 20 gallon. Having a tank in sunlight is not helping you ether. The good news is the fish will find food eating the floating algae that is green water. No harm to the fish.

With goldfish it will be impossible to have floating plants helping to consume some of the nutrients. The goldfish will eat any plants you have floating or in the tank.

Yes there are some of us that have green water tanks by choice . A heathy way to keep fish, it just looks terrible in some peoples eyes.
you will need a bigger tank with another species of fish that allows plants to grow to have a clear tank in sunlight. In a warm climate you may have trouble in the summer with the water getting to hot for goldfish?

 

we live on the third floor and the aquarium is placed in the balcony. Im ashamed to say this but they are actually 2 young koi. I was given them for my birthday. the 20 Gallon is the biggest tank I can have so I put them in there. thanks for the help though.

btw I do have a hang on back filter.

 

Enjoy the time with the fish as they grow a little under your care. As you probably realise you will have to let someone else look after them soon that has a pond or small lake.

 

yes. they are two really pretty guys. It'll be sad to give them away, thanks

btw I watched this one Youtube video and in the video, the guy said that you could add hair algae to your filter and it makes the water clear again. Is this true?

 

Using hair algae to filter microscopic floating algae is not something I am familiar with?

I have seen many U tube videos and am always open to the possibility of new ideas.

It seems likely you can filter MOST of the algae out but as you have seen it grows back quickly when the conditions that started it in the first place are not fixed?