High Naitrate problem.

[isaac]

Hi there.
I have a 40 gal tank 7 months old, i lost about 8 fish for the past 2 weeks. I have high nitrate that i can not get out of my system. I add more live sand, (total of about 5" inch), doing water change every 5 days, I have this problem for a bout 3 weeks and do not know what to do.
Please help. :help:

 

[fisherson]

how high is high?
Do you have a protein skimmer?

 

[lion_crazz]

also, do you have a clean-up crew? What were the 8 fish in the 40 gallon?

 

[isaac]

I have about 40mg and have a protien skimmer.

 

[isaac]

2 Blue tang, fire shrimp, Mandarine, gobie.and yes I do have a clean up crew.

 

[caomt]

what did you recently add?

 

[fisherson]

Blue tangs like a lot of room to swim and are hard to keep anyway. Mandarins need LOTS of rockwork and if you don't have a fuge for breeding pods the food suply will dissapear.

 

[isaac]

what is fuge

 

[scubadoo]

You have a nutrient source...overfeeding, tapwater, etc. I believe the others have covered the issues with tank size, fish and requirements. Tangs are big waste producers too.