Nitrate Spike

[fredso2003]

:roll: I have a 100 gallon reef tank,the tank is very deep approx. 40" deep and 38" round in circomfrence.I do not have a sump.Filtration consists of a fluval 304 and marine land 300,both canisters.I have a red sea protien skimmer that seems to be doing its job,I also have 4 power heads positioned at top and bottom of the tank.Lighting is 1 400 watt metal halide,3 atenics,1 40 watt and 2 20 watt.Lighting is 11 hours m.h. and 4 hours atenics.The tank is 8 months old.My salinity is 1.23,nitrites 0.5 or less,amonia is 0,calcium is approx. 500 ppm,live stock is 2 tomato clpwns,2 true perculas,2 chromisis,1 mandarin goby,2 yellow tail damsels,50 hermit crabs,25 turbo snails,2 brittle stars,1 haitian purple tip anemitie.I have approx. 5" agrogate crushed coral bed with lots of bristle worms and cocapods.The corals are 1 pagoda,1 frogspawn,1 torch,1 candy cane,a colony of green zoanthoids,some green star polyps and large brown mushrooms and purple mushrooms,and 75 lbs. of live rock. My big problem is that for 7 months i was detecting less than .05 ppm nitrate levels,in the last 2 weeks it has risen to .20 to .25 ppm,i do 10%water changes 2 times a month,that is not bringing them down.I started dosing with kalkwasser recently to maintain calcium levels and i add a buffer to maintain an 8.3 alkalinity,I could use some help in finding out why this spike in nitrates has occured?I even changed the carbon in my fluval after last water change last week and still no reduction?i also sucked out some of the debri in my agrogate bed.PLEASE HELP!

 

[WannaBeReefer]

Are you sure all occupants are accounted for? Maybe one died.

Just a guess

 

[Len]

The spike could simply be from you liberating some nutrients when you siphoned the sandbed. That's still very low NO3 levels and I wouldn't worry about it. Nitrate isn't very toxic and if you aren't experiencing an algae bloom, it's of minimal concern with levels as know as you've tested.