Reduce Nitrates through better lighting

My reef tank has been up and runnning for 14 months. Over the summer my nitrate level went to 25 ppm and stayed there for months. I added a refugium with a deep sand bed and Chaeto algae but the nitrate level didn't budge. At the end of October I became concerned that I didn't have enough lighting because my PC bulbs had aged. I went to the hardware store and bought 4 23W spiral fluorescent bulbs with a color temp of 6500K and four shop light fixtures with reflective hoods as a temporary fix. After four days my nitrate level dropped from 25 mg/L to 10. Three days later it was down to 5. It has been 5 weeks and my nitrate level is now at 0.2 as measured with a Salifert kit. I was wondering if anybody has ever experienced the same think. You can read more on my reef blog at http://paulsreef.blogspot.com/2008/12/increasing-illumination-to-reduce.html. Please let me know what you think.

 

like the graph very much shows that adding the lights was a major contributor to the drop in nitrates. Was there anything else that changed or was that it. Just a guess but chaeto could have taken a month to become well established. Then again chaeto could have enjoyed the new lights making it more established. Karma for a good study

 

Probably a combination of chaeto and the lighting

 

10acre, The chaeto is in the refugium. It's lit by the same type of bulb on a reverse cycle. The only other thing that changed was tht within a week or two of adding the bulbs I ran out of Kent Tech-I. I was dosing twice a week. It's unlikely that this impacted anything since I saw such a big change in just 3 days.

 

Were the lights you mentioned(spiral PC) on the main tank or 'fuge? If main tank, thanks very little light, if on fuge, well its possible.... I've met reefers from downsouth that use natural sunlight to light their 'fuge!

The only way your hypothesis could become more solid is with a constant tank to compare against....

Good luck

 

Both. When I added the Chaeto to the 'fuge I added a spiral bulb. It was the brightness of this bulb that made me realize that my main PC fluorescents had aged and were way too dim. I ran out and bought 4 more spirals for the ain tank and ordered new PC bulbs for the main tank shortly thereafter.

There is no way for me to duplicate the conditions. What I'm hoping is that other people with high nitrates try the same thing to see if they can duplicate the results.

 

To be honest, I can't imagine anyone else throwing PCs of that nature onto a DT, but maybe.....

 

I have never come across this topic, nor have I ever heard of light bulbs reducing No3 levels. It doesnt mean that your hypothesis is wrong, I just dont see the connection. I think its the refugium that kicked-in and now your enjoying the benefits of one. Luna

 

The spiral bulbs were originally meant to be temporary. I guess the point I'm trying to make is that adding 6500K lighting in any form can help reduce nitrate levels by encouraging more algae growth. There is no reason why you can't build a nice hood to house the bulbs.

 

Speaking of low spectrum bulbs, I forgot where I read it, might have been Joshi, but someone was hyping 3500k bulbs saying the PAR was through the roof!!!

Sorry to thread jack