Algae Scrubbers

1. Algae Scrubbers How They Remove Nutrients From Your Aquarium by SantaMonica

2. Part 1 of 6What is an “algae scrubber” ? • It’s a device which uses algae to “scrub” (remove) nutrients out of your water. • It grows algae on purpose, where you want it, so nuisance algae grows less where you don’t want it. • It does this by consuming nutrients in the water that nuisance algae need to grow.

3. What is an “algae scrubber” ? • Since the algae grow in a place you can get to (inside the scrubber), you can easily remove the algae and throw it away. • And, since many aquarium animals love to eat fresh algae (especially green), you can feed some of the algae back to them. • Most of the algae, however, will be thrown away. This removes the nutrients from your water.

4. Part 2 of 6How did scrubbers develop ? • Algae scrubbers were invented by Dr. Walter Adey in the late 1970’s when he was at the Smithsonian Institution. • Algae, of course, had been grown long before that, but not in a manner so separated from the aquarium. • This separation is what keeps animals from eating the algae, and, allows you to remove the algae so easily.

5. How did scrubbers develop ? • Dr. Adey never built or sold any scrubbers, but he did license a few people to build them. • These designs were bulky, mechanical dumping buckets that were placed above the aquarium or sump. • They were noisy and not very reliable, and were also hard to build, thus they sold poorly and were discontinued.

6. How did scrubbers develop ? • In the early 1990’s a few people started making a flowing-river version of an algae scrubber. • It was easier to build, but still very bulky, and still needed to be placed above the aquarium or sump which took a lot of space. • It too was discontinued after a few years.

7. How did scrubbers develop ? • In August 2008, an internet forum user called “SantaMonica” posted his idea of a waterfall version on one of the aquarium forums. • This design had the first 2-sided algae attachment surface; this helped filtering but it still needed to be placed above the aquarium or sump. • It was built by many people and introduced scrubbers to a new group of internet aquarists.

8. How did scrubbers develop ? • In 2011 “SantaMonica” invented the upflow version, which uses air bubbles instead of a waterfall. • It is able to be operated inside of an aquarium or sump, instead of above it. This saves a lot of space for some people. • It is used by many people who don’t have room above their sump or aquarium.

9. Part 3 of 6How do scrubbers really work ? • The main filtering function of an algae scrubber is done by photosynthesis. • Light is combined with nutrients (nitrate, phosphate) to produce living algae. • The more algae that can be produced per day, the more nutrients will be used from the water per day.

10. How do scrubbers really work ? • In particular, photosynthesis uses (absorbs) nitrate, nitrite, phosphate, ammonia, ammonium, CO2, iron, and other heavy metals. • Ammonia is the preferred nutrient because it supplies nitrogen directly to the algae. • When ammonia is not available, such as in established aquariums, nitrite is used next, followed by nitrate.

11. How do scrubbers really work ? • Metals including iron are usually in ample supply in aquariums, especially saltwater tanks fed with nori, or freshwater tanks topped off with tap water. • Heavy metals, sometimes supplied by salt mixes, can also supply the growth needs of a scrubber. • Iron dosing, and possibly also iodine dosing, can sometimes help a scrubber grow if metals are lacking in the water.

12. How do scrubbers really work ? • Carbon is also needed for photosynthesis to occur, and thus for algae to grow in the scrubber. • The photosynthesis prefers to get carbon from the CO2 in the water because this carbon is easy to utilize. • If CO2 becomes low in the water, such as when a fast growing scrubber uses it, carbon is then pulled from the water’s alkalinity.

13. How do scrubbers really work ? • Light: the green algae that works best in scrubbers prefers mostly red light (660 nm) to grow. • Some blue light (430 nm) may also help, but many scrubbers have shown good results without it. • The strength of the light is very important, because if it’s too weak, only dark algae will grow, and if it’s too bright, no algae will grow.

14. How do scrubbers really work ? • Air/water interface: This is the hardest part to understand, but is what allows scrubbers to out-compete nuisance algae. • By using an air/water interface to make an extremely thin layer of water touching the algae, the “boundary” layer of water is reduced. • A boundary layer is like a wall; a smaller one allows more nutrients to reach the algae faster, and results in more nutrient removal.

15. How do scrubbers really work ? • Waterfall and horizontal river scrubbers achieve the this thin layer of water by using rapidly flowing water across a surface. • Upflow versions achieve it by passing air bubbles rapidly up a surface. • The areas of the surface with the most turbulence (air/water interface) will grow the most, and thus remove the most nutrients from the water.

16. How do scrubbers really work ? • Lastly is attachment surface: The surfaces of a scrubber must be very rough so long green hair algae can attach and not flow away. • Strong filtering will cause this long algae to grow in a scrubber, and it will be pulled on by the strong turbulence. • Filtering therefore will be proportional to the roughness of the attachment surfaces.

17. Part 4 of 6Operation • Picking the proper size scrubber is the first step; size is based on how much you feed, instead of how much water you have. • This is because scrubbers remove nutrients directly, and nutrients come from food directly. • More (or less) water volume in your tank would not change how many nutrients you are feeding each day.

18. Operation • However, one hidden source of feeding that confuses many people is nutrient-soaked rocks; in particular, phosphate-soaked rocks. • Rocks from previous tanks that had algae problems, or even rocks from your current tank if more than 12 months old, can be phosphate-soaked. • These rocks will slowly release the phosphate back into your water, exactly as if you are feeding more than you really are.

19. Operation • Therefore, when choosing a scrubber, add up how many frozen cubes, or sheet of nori, or pinches of flake, or grams of pellets that you feed each day. • If you have phosphate-soaked rocks, add 1 cube of food for every 50 pounds (23 kg) of rock. • The total number (feeding + rocks) is what you would use to determine what size scrubber to get.

20. Operation • Follow the scrubber directions, but generally, all scrubbers can start operation in a similar manner: • Set the lights to be on for 18 hours per day (all algae need time to rest). WATCH the light turn off, to make SURE it goes off when you think it does. • Make sure the water flow, or the air bubbles, are on for 24 hours per day.

21. Operation • After 7 to 14 days, see how the growth looks in the scrubber. • Black growth means it needs more light (just like a dark room needs more light), and white or yellow growth means it needs less light. • When the attachment surface seems full, clean it for the first time; generally this first time will be done in your sink with running water.

22. Operation • Repeat the cleaning process every 7 to 14 days, depending on how fast it grows. • In saltwater, when thick green hair algae grows, you may be able to just reach in a grab the growth without taking it to your sink. • Freshwater growth is much more like slime, and will usually need cleaning in your sink.

23. Part 5 of 6Results • When your scrubber has been growing thick growth, it can be the only filter on your tank, even replacing water changes. • It will remove: ammonia, ammonium, nitrite, nitrate, phosphate, CO2, and heavy metals. • It will put into the water: oxygen, amino acids, vitamin C, baby pods, and it will raise the pH.

24. Results • It will remove the nutrients needed by such nuisance algae as slime, turf, green hair, bubble, dino’s, and green dust; it will then help remove cyano too. • Dino’s are the first to go; cyano is the last. • It will lower the nitrate and phosphate; sometimes the levels will be too low to measure.

25. Results • Don’t forget that some of the algae from the scrubber can be fed back to your animals. • By feeding your animals with growth from the scrubber, and less from packages, the animals get live fresh food and no additional nutrients are added to your tank. • The growth can also be used for fertilizer, pet food, skin wraps, beer/wine fermentation, and even as a salad!

26. Part 6 of 6Advanced • For those wishing to DIY their own scrubber, or delve into advanced topics: • There are many upflow, waterfall, and river versions that are easy to build in a weekend. • A special aquaponics setup can be built which grows food for you, while filtering the water for the fish.

27. Advanced • A special seaweed cultivation version can be made using fertilizer and no fish, which only grows food for you. • Scrubbers can be used to deal with chlorine and chloramines in tap water. • Scrubbers can be used to do all your fish feeding, so that you never have to feed again.

28. Advanced • A quarantine/hospital tank can be set up so that it is waiting for use, with only a scrubber for filtration. • Upflow versions can allow ponds to be set up, including reef ponds, which have no external equipment. • Upflow versions can be put into your display, so that you do not need a sump.

29. Advanced • Large versions can be built to filter your outdoor pond, and even your swimming pool. • Tiny versions can be build into the back of your desktop tank.

30. End Thanks for reading!