High Nitrates

[Jeana]

My nitrates keep creeping up. I would love to hear you thoughts and ideas of how I can resolve. My tank is a 90 gallon tank and I do ~25 gallon water changes every 1.5 months or so. My last water change was 11/4/18.

Current parameters as of 12/19/18:
salinity: 1.0245
pH: 8.2
nitrate: 40 ppm
kH: 161.1 ppm
calcium: 440 ppm
phosphate: 0 ppm

I have a ~ 20 gallon sump below my tank that contains a diablo protein skimmer. Pictures are included of my set up. I also have an LED and metal halide light above my aquarium and another LED for my sump. The lights are on an alternate schedule.

Inhabitants include many corals, 1 scopas tang, 1 maroon clown, 1 watchman goby, 2 peppermint shrimp, 2-3 sexy anemone shrimp, 1 coral banded shrimp, hermit crabs, snails, 1 red banded goby, 1 mandarin goby, 1 royal gramma, 1 brittle starfish.

I also have a mermaid fan plant and a shaving brush tree.

I use a 5 stage spectrapure RODI system to filter the the auto make up water and water change water.

Any ideas, or is this normal?

 

[cromag27 Verified Sponsor]

more and/or larger water changes.

 

[acro-ed]

Are you having any issues other than the 40ppm reading?

 

[Mical]

How much do you feed and how often?

 

[speedstar]

Do you vac the sand bed or have a power head for flow under around the rocks?

 

[Jeana]

Are you having any issues other than the 40ppm reading?

Not that I'm aware of.

 

[Jeana]

Do you vac the sand bed or have a power head for flow under around the rocks?

I vac the sand bed in the sump, not the main aquarium. I have pretty good flow in the main tank. I have a maxspect wave maker.

 

[Jeana]

How much do you feed and how often?

I feed once per day A couple of squirts of frozen food from a pipette. Then every 3 days or so a squirt of zoo and phytoplankton along with a sheet of seaweed.

 

[fish farmer]

Just curious, why are you lighting your sump? I don't see much in there for macro algae.

 

[Jeana]

Just curious, why are you lighting your sump? I don't see much in there for macro algae.

I have a plant in there.

 

[Jeana]

I have a shaving brush plant there and It has some good nitrifying bacteria growing on some of the rocks. I also have a small amount of caulpera

 

[Mical]

Are you running filter socks and how often are you cleaning skimmer?

 

[Jeana]

Are you running filter socks and how often are you cleaning skimmer?

No filter socks. I clean the catch pot at the top of the skimmer when it gets full or when I do I water change.

 

[ReeferReefer]

I would rework your sump for more nutrient export.

If it was me I would vacuum out all the stuff in your second sump chamber and get some cheato or calurpa to put in there. Replace the light with a $100 led growlight.

The cheato will eat up the nitrates.

 

[Jeana]

I would rework your sump for more nutrient export.

If it was me I would vacuum out all the stuff in your second sump chamber and get some cheato or calurpa to put in there. Replace the light with a $100 led growlight.

The cheato will eat up the nitrates.

Can the cheato not go in with the gravel? The shaving brush I have in there needs substrate.

 

[ReeferReefer]

Can the cheato not go in with the gravel? The shaving brush I have in there needs substrate.

The gravel can stay. It just tends to gather up detritus. Shaving brush is a super cool macro but I would recommend a faster growing macro to serve as nutrient export. TBH Cheato or Calurpa would likely overtake the shaving brush, as they are such good growers. Thats what makes them so good for pulling out Nitrates.

 

[rkpetersen]

Nice looking softie tank! First, definitely agree more water changes will have maximum impact on nitrate while leaving everything else relatively stable. A refugium area with chaeto and perhaps a second fast growing macroalgae like ulva or gracillaria is a great natural way to get your nitrate down without much risk, but it takes time to get a decent mass of algae growing. If you want to keep the shaving brush I'd maybe put it in the tank because it won't get much light in the sump with a good mass of chaeto growing over it. There are other means of nitrate reduction such as carbon dosing, but those also push phosphate down and with yours already at 0 that could be trouble for some corals. Or you could try setting up a denitrifying area in your sump; some people report success with Marine Pure blocks and Siporax rings, but both of these media have also been shown to leach minerals into the water. Also you could consider adding filter socks temporarily and cleaning them every 3 days.

 

[Gage Sullivan]

I need HELP! I have very high nitrates in my 45gal with 10gal sump. I literally have ONE fish, a octo 50 skimmer, a fuge with macro, and have been doseing vodka to take care of nitrites. What is causing them to rise? I do a 10% water change every week and the tank is a little older then a month old. I have a few lps. Do I need a CUC? I know I will, but figured with one fish I would be ok without one for a while.

 

[chefjpaul]

What are you using to test?

If it is that high and you want it lower, good nutrients reduction advise as stated above utilizing your refugium effectively will probably be all is necessary.

 

[Jeana]

Nice looking softie tank! First, definitely agree more water changes will have maximum impact on nitrate while leaving everything else relatively stable. A refugium area with chaeto and perhaps a second fast growing macroalgae like ulva or gracillaria is a great natural way to get your nitrate down without much risk, but it takes time to get a decent mass of algae growing. If you want to keep the shaving brush I'd maybe put it in the tank because it won't get much light in the sump with a good mass of chaeto growing over it. There are other means of nitrate reduction such as carbon dosing, but those also push phosphate down and with yours already at 0 that could be trouble for some corals. Or you could try setting up a denitrifying area in your sump; some people report success with Marine Pure blocks and Siporax rings, but both of these media have also been shown to leach minerals into the water. Also you could consider adding filter socks temporarily and cleaning them every 3 days.

I used to have filter socks, but I found that it killed a lot of my copepods and I have a mandarin goby that needs those for food, so I stopped using them. Also, do the filter socks have a life expectancy? I had my filter socks for a little while, but it seemed like I could not get them clean.