Keep Reef Tank Nutrients in Check With an Algae Turf Scrubber
The primary function of your aquarium's filtration system is to export nutrients that are introduced into the aquarium via food and the resulting waste byproducts from your aquatic pets. Since an aquarium is an enclosed ecosystem, the only way for nutrients to get out of the aquarium is via filtration.
In most scenarios, we are employing a multitude of nutrient export techniques in order to maintain a healthy environment for our aquatic pets. From simple filter socks and water changes to more complex things like a protein skimmer or reactor. In the last 15 years or so, algal filtration techniques have really come around because they are low maintenance, and once installed, they really don't cost much to maintain outside the electricity to supply light.
Algal Filtration: Implementing the controlled growth of algae in a dedicated "chamber" to effectively remove nitrate and phosphate from the aquarium water.
Why Choose a Turf Scrubber?
While both refugiums and chaeto-reactors rely upon macroalgae to sequester nutrients, an algae turf scrubber is unique in that it promotes the growth of microalgae, Turf Algae to be specific. Turf algae are fast-growing and more efficient at removing nitrogen than chaetomorpha. Anecdotal tests have revealed up to 50% more nitrogen by weight in turf algae compared to chaetomorpha. Under ideal growing conditions, an established turf scrubber can pull up to 30 ppm of nitrogen per day. Since algae uptakes CO2 as it grows, you get less carbonic acid in the water and therefore less suppression of your tank's natural pH level.
Another great benefit is that scrubbers take up less space than alternative algae-based filters and are incredibly easy to get started. In 99.9% of tanks, turf algae already exist in your aquarium so you don't have to source the algae itself, just install the scrubber and turn on the lights! Within a short time, the algae begin to grow and will require harvesting every 7-10 days thereafter to physically remove the nutrients.
How to Use a Turf Scrubber
There are a few different turf scrubbers on the market with certain installation requirements so just be sure you choose the appropriate size scrubber along with any required plumbing and, of course, a pump to push water through the scrubber.
Keep in mind, turf algae require nitrogen, phosphate, and a variety of trace elements to grow, and that growth will only be maintained as long as these nutrients are available. Test your nitrate and phosphate levels before getting started; ideally, your ratio of nitrate to phosphate will be roughly 10:1 - 12:1 which has proven to produce the best results in terms of turf algae growth.
- Install the scrubber and attach the pump. Be sure the pump is creating a sheet of water that covers the algae screen evenly all the way across.
- Connect the lights to a timer or controller and start with lights running 24/7.
- After 7-14 days the algae will begin to grow. Test your aquarium's nitrate level.
- After the first initial harvesting of algae, you can reduce the photoperiod to achieve less aggressive nitrate removal as needed to maintain your desired levels. Shorter photoperiod = less growth = less nitrate removal
- Create a test result log with both nitrate and phosphate levels recorded weekly to monitor the scrubber's performance and nitrate-to-phosphate ratio.
- Dose trace elements at least once per week to ensure optimal conditions for the turf algae. If your nitrate or phosphate ratio begins to fall out of sync, you can dose using nitrate or phosphate additives such as Brightwell Aquatics NeoNitro and NeoPhos.
- Harvest the algae every 7-10 days.
Many reef tanks struggle with maintaining adequate trace elements, even without a scrubber. Turf algae will consume trace elements and if you struggle to maintain steady algae growth, trace elements are likely the cause so long as nitrogen and phosphorous are available. Brightwell Aquatics Chaetogro or similar trace element solutions are recommended and will be necessary for long-term performance.
Turf Scrubber FAQs
- Nitrate and phosphate must be present and at the proper ratio for turf algae to grow consistently. A nitrate-to-phosphate ratio in the 10:1 - 12:1 range is the target for healthy turf algae.
- Adjust the photoperiod to dial in the rate of nutrient export only after the screen has grown its first sheet of turf algae
- Be sure the correct flow rate is supplied creating an even sheet of water over the screen
- Dosing trace elements will likely be necessary for sustained growth. Turf algae cannot survive on nitrogen alone.
- Turf algae will consume various heavy metals and a variety of other trace elements along with nitrogen and phosphorus; one might say it's "nature's garbage disposal".
- You must harvest the algae (clean the screen) regularly to experience consistent removal of nitrate and phosphate; removing the algae is how the sequestered nitrate and phosphate are physically removed from the aquarium.