Q: I'm getting cyano on my screen. Is this good?
A: No. It means your light is too weak or too far away. Regular algae (green, slime, brown) should be the only thing growing.
Scrubber Comparisons:
Q: How is a scrubber different from a skimmer?
A: Scrubbers remove Inorganic Nitrate, Inorganic Phosphate, ammonia, metals and CO2 from the water. (Inorganic Nitrate and Inorganic Phosphate are what cause nuisance algae to grow on your rocks and glass, and are what you measure with your test kits.) Skimmers remove Organics (food) from the water. Both scrubbers and skimmers, however, add oxygen to the water. Scrubbers add more, however, and can supersaturate the water with oxygen.
Q: How does a scrubber compare to a refugium with macros?
A: This is a long one, and is detailed here elsewhere on the web.
Q: How does a scrubber compare to a denitrator?
A: A denitrator removes nitrate. A scrubber removes nitrate, nitrite, ammonia, phosphate, CO2 and metals. Also, a scrubber cannot harm a tank, whereas some denitrators, if adjusted improperly or if they malfunction, can put harmful chemicals into the water.
Q: How does a scrubber compare to GFO (granular ferric oxide) phosphate removers like RowaPhos and PhosBan?
A: GFO's do remove phosphate, although they may lower the pH while doing it. And they are expensive. Scrubbers remove phosphate, as well as nitrate, nitrite, ammonia, CO2 and metals, and do so while increasing the pH. And once built and installed, a scrubber does not need to be "refilled". Also, if GFO bag or canister spills, or if you accidentally drop some in, the GFO will go everywhere throughout your sump/pumps/tank. If you drop algae in the tank, it's no different from algae that's already in the tank.
Q: How does a scrubber compare to a Remote DSB (RDSB)?
A: RDSB's removes Ammonia, Nitrite and Nitrate. Scrubbers remove the same, in addition to phosphate, metals and CO2. RDSB's, however, just like regular DBS's, tend to store phosphate in the sand during high-nutrient times. It then releases the phosphate during low-nutrient times. Scrubbers don't "store" phosphate; the phosphate is "in" the algae that grows, and it is then removed during weekly cleaning.
Q: How does a scrubber compare to vodka (carbon) dosing?
A: Both remove nitrate and phosphate. Vodka, however, requires a skimmer to operate (to remove the bacteria that grows), and this skimmer thus also removes food from the water. Vodka also reduces the oxygen in the water (bacteria use it). Scrubbers don't require (and work best without) a skimmer, and they add oxygen to the water. Lastly is the safety issue of vodka: If you carelessly pour it from a bottle, and pour "just a few ounces too much", your entire tank will be dead in a few hours. With a scrubber, there is nothing that can happen which would cause such a situation.
Scrubber Applications:
Q: Can I put a scrubber on my nano?
A: Yes, you can make/put a scrubber on any tank. There are two types of nano's: Those with a hatch on the top that let you get to the filter area, and those where there is no hatch (like Aquapods) where the whole lid opens up as one unit. Aquapod types are the hardest to add your own scrubber to; however the hatch-on-top types are the easiest.
Q: Have scrubbers been used for breeder or retail tanks?
A: They are being tested now.
Scrubber Advanced Topics:
Q: What exactly does a scrubber do to my water?
A: It takes ammonia, nitrite, nitrate, phosphate, metals (like copper), and CO2 out of the water. It puts oxygen into the water. It also cools the water. And if you put a fan on it, it REALLY cools the water. Increased evaporation, of course, will also occur. Copepods are added to the water. Iron and Iodine are removed from the water, but they are of lesser importance, and are removed to a lesser degree, than the above items. Alkalinity may in some cases be slightly decreased, because of algae's slight use of bicarbonate to get CO2. Water clarity is sometimes improved, because of the increased oxygen (similar to ozone).
Q: What if there is a power outage? Will my scrubber die?
A: In most cases you will loose your tank before you loose your scrubber. With no power (and thus no flow, and no lights shining on the algae), the outer layer of algae hardens and keeps the inside layers wet. Six hours should not be a problem.
Q: I've heard you have to "pulse" or "surge" the water to get best results.
A: This is not proven yet. Most scrubbers use a constant flow, and have great results.