By Bob Goemans
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Bob Goemans corresponds with Colby & Jordan (London, Ontario)

Colby & Jordan (London, Ontario) writes...

Dear Bob,

We have read your book on protein skimming and activated carbon and we have a few questions. We have a 46 gallon marine aquarium with 55 lbs. of live rock. There is no substrate and we have been using a Eheim canister filter with only pads for mechanical filtration. We have never used any type of media in the filter. The tank has been running for about 6 months now and contains 1 Picasso Trigger, 1 juvenile Clown Trigger and 1 Black Damsel. There are no invertebrates. The fish are fed mysis shrimp and krill four times a day. As of late we have been having a difficult time with our nitrate level. We can't get it below 20ppm and it is usually closer to 50ppm. We would like to know if we should be using media in the filter and/or a protein skimmer. We have avoided the use of media as we would prefer our rock to be a natural biological filter, however maybe the rock is not adequate. If a protein skimmer is the answer, please enlighten us as to which type would be best. (There are so many on the market and we are so confused; we have been considering the Red Sea Prizm) Any information you can provide for us would be most appreciated. Thanks so much.

Colby & Jordan

London, Ont.

Bob replies...

Hi Colby and Jordan,

I had a similar tank about ten years ago. It was a 75 gallon and contain a large lionfish, moray eel, and triggerfish. Its nitrate was always near 100 ppm, yet none of the fishes appeared interested in anything but three meals a day. In other words, high levels of nitrate are not a problem in some fish-only tanks. Where you are concerned, I would not be even slightly concerned. However, if nitrate climbs a lot higher, Aquarium Products makes a plastic chip-like media called �Nitrex.� When half a box of it is placed in another product called the �Nitrex Box� is oxidizes nitrate back to elemental nitrogen gas. One box of media will handle a 60 gallon aquarium. I used three boxes as an experiment in my 75 and was able to reduce nitrate to about 40ppm. Its still sold and can be found in mail order catalogs. About twenty dollars for a package of Nitrex and the box. As for installing a skimmer, it would possibly help lower nitrate and help further oxygenate the bulk water. You could not go wrong by adding it.




Protein Skimmers; Nitrate Problem

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