There are a few different methods that can be used in this situation.

One of the most poular is to use a product such as Biopellets to deal with the nitrate and help with the phosphate issue. The bulk of the phosphate can be removed with a good quality phosphate remover such as Rowaphos.

Start with using 100ml of Nutrifix Biopellets per 100 litres of aquarium water. This can be increased to 200ml per 100 litres but it is best to start with a smaller ammount and build it up slowly. Biopellets need to be run in a fluidised reactor such as the FMR75 or the Deltec FR range. The Pellets in the reactor will need to be fluidised well, this will keep the pellets from binding together as the bacterial mulm that consumes the nitrates develops.

When running Biopellets it is also important to run an efficient protein skimmer as the bacterial mulm will need to be skimmed off. If possible it can also help to direct the outlet from the pellet reactor towards the inlet of the skimmer, take care not to restrict the skimmer when doing this. The skimmer will also help and too keep the water well oxygenated as bacterial respiration can take up some oxygen.

Use Rowaphos to bring phosphate levels down to around 0.02-0.04ppm. It is usually best to start with about 50% of the recommended amount of the Rowaphos. The nitrate reducing bacteria require trace amounts of Phosphate for cell reproduction, as do all living things, so be carefull not to reduce the phosphate to zero.

We advise the use of a fluidised reactor when using Rowaphos but if space is limited you can use a media bag although the phosphate take up by the media won’t be quite as efficient.

Do not put the Rowaphos and the biopellets in the same reactor. The biopellets will need a much higher flow rate than you will be able to successfully pass through the Rowaphos.

Once the nitrate and phosphate are under control the algae growth should naturally decrease. If nitrate and phosphate issues are a constant problem it may be worth checking that the aquarium is not being overfed or feeding small amounts more often than larger amounts less frequently.