Unexplained high nitrate levels

Question
My 120ltr tank has been going for 7 mths now.I have 1maroon clown,blue damsel,coral beauty and a blue chromis.also have 6 small soft corals also very small blue clam plus live rock.up to a week ago all my parameters were excellent.I did my weekly chck and the nitrate was over 80,did 20% w/c.didn't correct it.today I did a 50%w/c but nitrate still over 80.the only thing that I can think of is that I added a dead clam shell I bought off my lfs this little thing have caused my nitrate problem.I've spoken to my lfs and they couldn't really help me.my skimmer and air pumps are all fine .help !!!!

Answer
Hi Jacki,

Good questions. In the U.S. we use gallons, therefore you are referring to a 30 gallon aquarium.

Regarding the added dead clam shell, this would not raise your nitrate levels none whatsoever, of course unless the dead clam was still in the shell, decaying in your water.

Regarding finding the main culprit of what is excessively raising the nitrates in your aquarium: (see my recommendations/suggestions below)

-- I recommend to thoroughly test the water that you're using to do your water changes with; make sure this water doesn't have a high nitrate reading. I recommend to use reverse osmosis water.

-- If your aquarium has a built-in overflow filtration system, that implements bio-balls, make sure the bio-balls don't have an excessive build-up of matter on them;  also make sure the bio-balls compartment is not jammed packed with bio-balls, if it is, take some out, you want sufficient water flow around them at all times. Also if you're using filter floss or a filter sponge in your sump compartment check it, and replace and/or wash out if needed.

-- I also recommend to add a better more efficient protein skimmer, which will drastically help keep dissolved organics out of your water, therefore helping to keep nitrates down. There are plenty on the market, specifically designed to fit nano aquariums of 30 gallons.

-- I also recommend to occasionally add a good beneficial live bacteria to your aquarium water during your water changes. A couple that I can recommend include Brightwell Aquatics MicroBacter 7, and TLC StartSmart Complete. These beneficial live bacteria help to keep your biological filtration at optimum levels at all times.

I hope the above information helps out, and I wish you luck with all your future saltwater aquarium endeavors.

Best Regards,
Dave

All Experts Editor

http://www.ocreef.com - Director