Algae on aquarium walls

by Viv
(New Zealand)

No matter how often we clean our aquarium it seems to become discoloured with an algae build up around the bottom walls. We have a 38ltr aqua one tank, have 2 small goldfish & 2 tiny ones. Any tips would be appreciated.



Grant's Reply


Hi Viv

If you are referring to the brown smudge at the bottom of your aquarium, it is a build up of diatoms, a single cell phytoplankton.

Water high in silica tends to promote diatom growth but there isn't a lot that can be done to remove it from the water supply.

Diatoms can coat everything in the aquarium including plants and ornaments as well as the aquarium sides.

They are harder to control as they don't require as much light to thrive as most green algae need and their reproductive cycle is much faster than other algae.

As for controlling diatoms, the first thing to do is ensure your water nitrate level is below 20 ppm (parts per million). A cheap water test kit will tell you that.

The aquarium seems to be receiving strong light from somewhere so I would consider moving it or blanking off one or both ends of the aquarium.

I use bristle nose catfish to control algae in my aquariums but they are tropical and need to be heated. Some also attack Goldfish to get the protein from their slime.

Because it is easily wiped off the sides of a glass aquarium, I also use a glass scraper available from any fish store.



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Aug 31, 2017
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Update re: algae in our tank
by: Anonymous

Thanks for the comments, we do regular water changes & have replaced our sponges recently so I am sure we are doing everything right.

This is the first cold water tank I have had, I have in the past had big tropical tanks with none of the problems I have had with this one. However I will wait & see if I have helped the problem by moving the tank.

Aug 29, 2017
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Think I've solved my algae problem
by: Anonymous

Thanks for the help, I suddenly realised a few days ago that our heat pump is on a wall directly opposite the tank so think that may be one of the main causes, we have moved it to another room with less light where it is so will hopefully have solved my problem.

Cheers

Aug 29, 2017
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the battle against grubby stuff growing on the walls
by: Minnesota Mom

We all know how to decrease nitrate, but for anybody who doesn't know how, it is the end product of the breakdown of food and waste. Partial water changes (10% every week, or 40% a month, up to 50% at any one time, but small regular changes are better) will decrease your nitrate, increase your good hardness, and give you a regular appointment to remove any debris pockets collecting in corners or behind decorations. Its also a good time to maintain your filter. If you have a sponge filter or sponge pre filter giving it a little squeeze in the water change water is a good way to remove debris & make sure that the water can flow well through the bio filter.

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