Our question today comes from one of our Facebook fans, Louis, who asks, "How do I get rid of and keep red slime out of my tank?"
Thank you for your question, Louis. Red Slime is a problem that most all reef aquariums will encounter at some point. The first step in conquering this pesky slime is having a good understanding of how and why this slime grows in your aquarium.
Red Slime is actually classified as a bacteria, not algae. It is a special type of bacteria called "Cyanobacteria" that has properties of both bacteria and algae. It is photosynthetic and also feeds off of waste in your aquarium. Elevated Phosphates and nitrates are going to be the leading water parameters that promote the growth of Red Slime. Sufficient water flow and proper lighting will also play a huge role.
Let's first address your water quality. You want to be sure that you are keeping up with regular water exchange and keep your mechanical filters clean in order to ensure nitrates levels stay as low as possible. You will want to also be sure that you are using something to control phosphates on a daily basis. The best method is using a phosphate reactor but you can also utilize a liquid phosphate remover. Even the smallest amount of phosphates can cause Red Slime and phosphates must be eliminated to prevent Red Slime from growing.
Once you have addressed your water quality, you can focus on removing the existing bacteria from your aquarium. You will notice a number of different Red Slime control products which will immediately and effectively kill any red slime growing in your aquarium.
Luckily, Red Slime is also very easy to remove via siphon which is my preferred method. This way you can immediately remove the bacteria without using any chemicals. I would recommend siphoning out the red slime when performing your weekly water exchange. If you do not wish to perform a water exchange, you can easily filter the aquarium water through a filter sock and into a container. Then simply pour the water back into your aquarium.
We have a great article located on our website that gives you more details, tips and tricks:
For more information about Red Slime removers and to read product reviews from other hobbyists, please visit our website: