High nitrates but corals are thriving?

I have two mushrooms, a little green star polyps, a toad stool and a open brain coral and a new torch. My ammonia and nitrites are all 0. My nitrates were at 5. Before I left for 8 days now its 40 ppm. I have 7 fish. A eshopp skimmer rated for 150 gallons my sumps rated for 200 gallons and maybe 60 to 70 lbs of live rock it's a 90 gallon tank. My corals have been growing my toad stool was my ugliest coral and now its one of the most beautiful the mushrooms are doubling in size. I don't get it. I use API I did the test twice. Can anyone explain where are some soures of nitrates can come from? I make sure my filter socks are clean. Any ideas?

 

n03 is an ally of softies, by new what exactly do you mean reffering to your torch? though a resistant LPS it might suffer negatively if exposed to prolonged periods of high n03. the open brain might not be to happy either.

you got pictures?

no3 is the end product of the cycle nitrogen. fish food waste and organic matter is broken down till it reaches nitrates after this the bacterial colonies wont be able to entirely remove it. hence the need for a water change as well as replenishing growth elements like calcium and magnesium.

this is from my understanding so dont take my solemn reply as source of knowledge

 

+1

While skimmers, etc remove some DOCs and lower Nitrate production, it will still build up in your system and must be removed via water changes.

 

Softs and some lps seem to like some nitrates.

nitrate source? So you have any other type filtering pad in your system? they can be a nitrate producer.

Was the nitrates 5 before your trip and 40 just afterwards? quite the jump. Who/what was feeding while youy were gone? Any chance of some overfeeding? etc.

 

you would have look a all possible sources for your nitrates. i run the aquaripure nitrate filter and my stay at zero.

 

Over feeding?

Are you running carbon?

How often do you do water changes?

Do you use RODI water?

 

I did have someone take care of my tank that was inexperienced all they did was feed then and I do a 15 gallon water change every week and it always jumps right back.

 

I might give up on this fight and get a aquaripure filter and there expensive could I buy a one that's less rated for my tank or do I have to go with the 280 dollar one.

 

You should always go with equipment that's rated for or over your tank. I'd look into BioPellets.

 

That right there jumps out at me.

Tank sitters always feed A LOT more than you'd like them to if they don't know what they're doing.