Advice on Nitrate Reducing Filters

[widdledink]

Because I have such a high Nitrate Level in my water does anyone suggest using an Nitrate Reducing filter like AquaMedic Nitratereductor? Does anyone use one? What are your results?

[kreblak]

Most products that claim to reduce nitrates are snake oil, in my opinion. The only proven effective method for removing nitrates from your tank is through regular water changes, and denitrifying bacteria. Does your tank have a deep sand bed and a lot of live rock? DSB's allow anerobic denitrifying bacteria to grow in the oxygen poor bottom layers, which convert your nitrates into carbon dioxide gas. Likewise, live rock is super porous which creates deep recesses within the rock where oxygen levels are low, thus allowing the denitrifyers to breed and reduce your nitrate levels.

My tank had significant nitrate problems until I switched over to a DSB. Regular water changes are also important. They help export nitrates. Make sue that the water you are using as replacement water is nitrate free, too. Often times, tap water has as much as 30 ppm of nitrate already in it. Dechlorinators do not remove nitrates, so start using reverse osmosis/deionized water in you aren't already.

[BrianH]

I've never used a nitrate reducer but have heard of them on other boards. Some people have said they work but I've also heard of tank crashes from them. The last 1 I remember was during a power outage. It seems that the reducer worked on the principle of slow flowing water being pumped thru a lot of tubing. This creates a low oxygen environment where the denitrifying bacteria live. The problem comes when during a power failure the water sits for an extended period of time in the low oxygen zone. When the power is restored, this water is automaticaly pumped back into the aquarium and can create a tank meltdown.

Another method as suggested by Kreblak is to use a Deep Sand Bed. The DSB also contains a low oxygen zone for denitrifying bacteria to consume the nitrates.

Brian

[wayne]

Well I hear they work, but are high maintenance. THey work on the principle of moving the water slowly through a media which is kept anaerobic rather than aerobic as is more usual.
Personally I'd try a sandeb sump or a macroalgae sump first - less hassle, and some beneficial side effects from maintaining a refugium