High Phosphates

Q. I've recently seen numerous ads for "algae scrubbers" claiming they are the only "natural" filters on the market. Is this true? Are there any other less expensive filters just as good for reef aquariums? I currently run two Biowheel 300s (four wheels), a Sea Storm 240 and a Sea Clone protein skimmer on a 55-gallon reef setup. Should I get rid of all these and replace them with a scrubber?

My aquarium holds 13 pounds of live rock, 25 pounds of seven-month old base rock, four anemones, open brain coral, thriving mushroom anemones, seven shrimp, a sebae clown, a coral beauty, and 11 Turbo snails. Everything seems fine: nitrate is 20 ppm, there is no nitrite, no ammonia, pH is 8.5, calcium is 425 ppm and phosphate is 0.8 ppm. Will an algae scrubber give me even better results? Will I be able to add more fish because of these results?

I've tried making home-made scrubbers, but only get red slime algae no matter how much or what type of light I use. My lighting consists of two Trichromatic 40-watt tubes (on for 10 hours a day), two 40-watt actinic tubes (on for 10 hours a day), and one 20-watt blue moonlight tube (on for 24 hours). Is this sufficient? Should I add more?

A. My feelings and views on algae scrubbers can be found in the book I co-authored with Julian Sprung (The Reef Aquarium, Volume One, 1994), as well as in an article I wrote in the Aquarium USA 1998 annual. I have also been seeing the various ads in the national magazines touting algae scrubbers and the wonders they can produce, I have read a few articles recently published in the scientific literature and elsewhere, and I have continued my discussions with some of the scientists who use this technology. I will, however, save my comments for a separate column.

Suffice it to say the main problem you are having with your aquarium can be traced to the same one cited in the previous letter — namely, the phosphates are very high! I know from another letter you sent me that you were having massive algae problems until you added your 11 Turbo snails. You need to ascertain where all that phosphate is coming from and deal with it. (See my reply to the previous letter for some ideas on possible sources and how to deal with them.)

I am a little puzzled, though, by your filtration system. With all the live rock you have in the system and only two fish, I don't understand why you have four biowheels and a fluidized bed filter on a 55-gallon aquarium. To me this sounds excessive, and may be another reason for the unwanted algae growth and high phosphates. If you were to remove these filters and upgrade your protein skimmer you would be a long way toward dealing with the algae problem, the high phosphates and even reducing the nitrates. Yes, an algae scrubber can do much the same, but as you have observed already, they are not easy to set up without seeding them with the proper algal cultures to begin with. As noted above, I will discuss algae scrubber filtration in more detail in a separate column.