How quickly should I reduce nitrates?

[Chrysus]

Hi all,

Recent tests have shown that the nitrates in my 40 gallon are super high, at least 80-100ppm. There are a variety of reasons including a heavily stocked tank, a dirty canister, and a general lack of maintenance, but obviously I want to get them back down and under control as soon as possible.

How much water should I be changing and how often? The last water change was two months ago. I am also switching salts. I have been using instant ocean orange bucket when mixing my own water or instant ocean purple bucket when buying water from the lfs (the last few water changes), and I am switching to Aquaforest Reef Salt. I do still have IO orange bucket if it would be better to continue with that salt for now.

I don't have any fish that I would consider very sensitive, they all seem pretty content in the tank as it is though so I don't want to send them all into nitrate shock. The only corals left are a leather, a cabbage, and a chili coral, and there is also a BTA.

Any advice is appreciated.

 

[Old Fritz]

Luckily nitrates aren't super hard on fish especially if the level rises slowly. Obviously 80-100 ppm isn't ideal. What test kit did you use?

I recommend doing a water change, start with a fifty percent today, and do another fifty percent tomorrow or sometime this week. After that I recommend waiting a few days before cleaning your filter media. I like to be on the cautious side with water changes and cleaning filters because I have had a tank restart the cycle process from doing a water change and changing the filter within too short of a time period.

 

[Old Fritz]

and to answer the salt question both are nitrate free so that shouldn't be your issue. I don't know much about the aquaforest salt, I just use the instant ocean.

 

[Chrysus]

Luckily nitrates aren't super hard on fish especially if the level rises slowly. Obviously 80-100 ppm isn't ideal. What test kit did you use?

I recommend doing a water change, start with a fifty percent today, and do another fifty percent tomorrow or sometime this week. After that I recommend waiting a few days before cleaning your filter media. I like to be on the cautious side with water changes and cleaning filters because I have had a tank restart the cycle process from doing a water change and changing the filter within too short of a time period.

Thanks! Just tested with the API test kit. I tested once, and then diluted 50% and tested again. That read probably a bit over 40ppm. I have the salifert test as well but unfortunately I’ve misplaced both the vial and the color chart. I did test it in an API tube and it turned bright bright pink immediately.

I’m not switching salt because of the nitrates specifically, I just wanted something a little more suited for coral. I know some people don’t like to switch salts quickly though so I wasn’t sure how to go about that.

 

[BayouReefer]

I would do 50% today then 25% Sunday and another 25% Tuesday. If you have filter socks I would change half Sunday and the other half Tues. but I suspect you will get a bunch of different answers. There is not a 100 % right way to do it.

 

[PatW]

I am not a fan of the API nitrate test kit. It is quick and dirty and approximate. If you want a rough idea, it is fine.

I use Red Sea Pro for nitrate. Salifert is also decent. And both are superior to API. If you use a LFS and they do water testing, I bet that they use Salifert and there is a good chance they will give you the bits you need.

At 40 ppm, you are still high but your fish should be fine. Levels that high will probably cause algae problems. I run nitrates at 2 ppm for an SPS tank. But some people like 20 ppm, others 10 ppm, and others 5 ppm. If you get below 20 ppm, you will be in the ball park.

 

[Chrysus]

Sorry that’s 40+ppm at 50% dilution, so 80+ppm in the tank.

My lfs only uses API unfortunately, and they’ve been out of stock on the Red Sea test. I was planning to pick it up though.

 

[fish farmer]

As other suggested a couple of big WCs, but if it were me I would just start getting back into the routine of WC's every couple of weeks, get back on the maintenance schedual. I assume you don't have a sump since you mention the canister filter, if you had a sump you could grow algae like chaeto.

I brought my nitrates from around 30 ppm to 5 ppm in a similar sized system with 15% WC every two weeks and growing chaeto. It took a few months but it came down.