Controlling high nitrate levels

[TheManichaean]

Hi all,

The nitrate levels keep rising past 80ppm in my 4 month old tank, and I'm looking for some advice on keeping the levels lower (20-30ppm). I recently added a brighter light, which is my main suspect, but I'd appreciate any input. More details below:

When originally cycling the tank, I performed 20% PWC's every two weeks. Since I found these high NO3 levels last month, I've been performing 50% PWC's every two weeks. Fish are fine.

The biggest change that I made to the aquarium was adding a brighter light--a 110W compact flurescent. This light runs 8 hours a day in addition to my 30W fluorescent strip which runs 12 hours a day. The tank is currently very lightly planted, but the plan is to increase the planting in the next few weeks.

This might be obvious, but could this light be the problem? While I've read literature that extensively outlines the causes of NO2 and NH4, I haven't found much on the causes of excess NO3.

Tank Stats:
65 gal fresh
T=80 deg F
pH=0, NH4=0, NO2=0, NO3>60-90ppm
Magnum canister filter (don't remember exact model, rated for 150 gal)
UG filter, two power heads
Approx 30" of community livestock (barbs, loaches, balas, pleco)




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[Billsgate]

My suggestion is to get some fast growing stern plants as soon as possible. Get 1 or 2 pots of hornwort or waterweed, or any easy stern plant. Once they reach the top of your water level, cut a piece of and replant. You'll have plenty of plants in no time, and with that lighting you shouldn't see any problems. You will see a drastic decrease in nitrates once these plants start growing.

HTH