Nitrates will not go down.

I have had this problem for about a month. My nitrates are about 40 right now. For the past 2 weeks i have done 18gallon water changes on my 75gallon reef. I use RO/DI water, I have tested the water prior to adding salt and after adding salt.... and the water is perfect.

I have tried to siphoned the sand bed..... I have rearranged my entire tank to clean under every rock. Still high nitrates.

I am clueless at this point.... not sure what the next step is..... And ever since the nitrates have been spiked i have had a red slime outbreak.....

Can anyone help me....

All other parameters are good.
Light 4-T5HO, 3 Par38 bulbs
Reef Octopus
18watt UV Coralife
Magnum HOB Filter
2-Hydor Koralia 750gph

 

yup...your stirring up your sand bed....that will release alot of nitrates...how deep is your saned bed and is is pure fine sand or argonite or crushed coral?

 

I agree with pierce. Moving everything around could even cause the tank to cycle. How long is it set up?

I would do 2 big water changes in a week then leave it alone for a little while.

 

Are you running a fuge and what is your bioload? And yes stirring things up may cause a spike but its not a cycle its just that you are releasing waste into the water where your biological filtration can break it down into nitrates. You may also want to run your skimmer on the wet side until you get this under control. Also, double check your feeding regime to make sure you are not overfeeding.

 

Guess I'm gonna go against the grain here, but "keeping things stirred up" is exactly what you want to do so it can be filtered out. My question is, how often do you check/clean your HOB filter? With SW, it will become a "nitrate factory" if not properly maintained, which can mean cleaning the pads 2 - 3 times per week and changing them more frequently than with FW depending on your bio-load and feeding.

As an aside, the presence of algae will affect your nutrient level readings as algae consumes the nutrients. What you will actually see is the result of the production/consuption ratio, or IOW, what's left.

 

Tank has been up for 11 months... I only stirred up the sand bed after i tried everything else..... The sand bed is about 3 inches

 

I have tried everything else before stirring up the sand bed....
The HOB filter is changed and cleaned once every 3-4 weeks..
I will try to clean it ever week for a while and change out the Carbon once a week.

I dont believe im over feeding... I have 12 fish... Most small Goby...2 clowns.... Atlantic Blue Tang, Blue hippo...and 3 bassets...I also have 4 shrimp, and a pistol shrimp. I feed a cube in the morning and evening.

 

No Fuge... I would like to run one along with a Sump.... but not there yet. And i dont understand "BioLoad" what is that.

 

IMO the best way to low nitrates just like Mr. Bill said is keep stiring things up and do water 10 - 18gal water changes every other day for 2 weeks i gaurntee that your nitrate problem will be gone if not there is another issue.

You might be over feeding but it sounds like your bioload is high 12 fish is alot. I only feed about every other day if not every third day, Most feed once a day though.

 

I think that this has already been asked but what is your bio-load (i.e. give us a list of inverts and fish), how often do you feed and how much?