How do I control algae from the very start?


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One reader is concerned about controlling algae in his new set-up.

I’ve been a fishkeeper for many years and am about to purchase a new 230 l tank for tropical fish, which will have an external filter. I want to be able to get on top of algae from day one and I’ve heard of controlling it with UV lights. Are there any that can be used in line with the filter so as not to have the light inside the tank? I’m also considering a CO2 unit to promote good plant growth. Any suggestions or additional advice on plants would be greatly appreciated. 


Jordan replies: Controlling algae in new set-ups can be a challenge. There are many factors to take into consideration to successfully mitigate severe algae blooms after setting up a new tank. 

UV steriliser products are available online and can be placed in-line with the filter tubing; the UV light is used to remove types of floating algae such as those that cause green water, but until such a critical scenario appears, it’s certainly not required. There are many alternative, more budget-friendly, measures that can be taken. 

Pressurised CO2 can be highly advantageous to growing healthy plants and therefore reducing the risk of algae. Healthy and faster growing plants can outcompete algae and deter it from getting into an unmanageable state.

Faster growing plants such as stem plants can certainly make a difference and it is always recommended to plant densely from day one to give your new set-up the best chance of success. If you don’t utilise CO2 or stronger light, then easy plants that can tolerate these conditions should be used.

Other factors to help reduce algae can include light control, tank cleanliness and biological maturity. Use of an all-in-one liquid fertiliser and nutrient-rich aqua soil are highly recommended to ensure a healthy plant mass. Frequent and consistent water changes in the first month are very important as well as long term weekly water changes in a planted aquarium.